This ended up being longer than I expected, but here you go. In case any new/returning players are wondering about the ins and outs of free-to-play, look no further.
The Free-To-Play Question-O-Rama and Also Hyphens
Specific details are slightly hard to come by, so here is everything that I could piece together through the SWTOR website's information (http://www.swtor.com/free
mostly), the test server/patch notes, and developer responses on the forum.
So what's this free-to-play thing, then?
Starting on November 15, new, returning, and current players will have the option to play the game without a subscription fee. You'll be able to level to 50 and experience basically the entire game, but with certain limitations. Also of note, if you want to start playing right now, the free trial (play up to level 15) still exists and all trial accounts will be converted to free-to-play ones when it launches. http://www.swtor.com/trial
Do I have to buy the game?
What are these limitations?
Spoilered for long.
Slower XP gain after level 10.
Limited races at character creation (only human, cyborg, and zabrak).
A cap on how many credits you can have. Increased cap for preferred status, unlimited for subscribers (or whatever the cap was for them before free-to-play launched, anyway). Extra credits you earn after the cap are placed in escrow, which is given to you if you subscribe/buy a month of game time (or 150,000 of it is given to you if you go up to preferred status).
Two ability bars. Suscribers get six.
Cannot do operations.
Five warzones per week. Unlimited for subscibers.
Three space missions per week. Unlimited for subscribers.
Rewards from only three flashpoints per week (can do them as many times as you want, just can't get item drops from them after the third).
One crew skill. Three for subscribers.
Can only gain access to the cargo hold and additional tabs with cartel coins. Subscribers have cargo hold access by default and can use credits or cartel coins to buy additional tabs.
Can only increase inventory with cartel coins. Subscribers have the option to use credits.
Longer quick travel cooldown.
Limited number (5) of field revives. Subscribers have unlimited field revives, though the increasing cooldown still applies.
No priority status for login queues.
Cannot use most artifact (purple) gear.
Cannot use the hide head slot or match color to chest piece cosmetic options.
No access to the guild bank.
Cannot display titles or your legacy name.
Almost all of these can be allieviated with cartel market purchases (either one-time permanent authorizations or weekly passes for operations/warzones/flashpoints/space missions), with the exceptions of the credit cap and login queue priority. If you want more than just a few, though, it'll probably be more cost efficient to subscribe.
What's this about Preferred Status?
If you've ever subscribed in the past, or you purchase $5 or more on the web store (cartel coins or the physical security key or whatever; more about the security key in a bit), you get Preferred Status, which has a few perks over a regular free to play account. This status is permanent: once you have it, you'll never go all the way back to the base free-to-play account.
Preferred status perks
So what was that about security keys?
Information about security keys
Sprint ability at level 1
Access to your cargo hold
Access to secure trade
Ability to send mail, including one attachment
Increased allowance for chat message frequencies in public chat channels (such as /general)
Increased Credits cap
Access to the Who list (player search)
Three additional sale slots on the Galactic Trade Network, for a total of 5 slots
One additional Crew Skill slot, for a total of 2
Reduced skill point respecialization costs
Increased server queue priority
Okay, so if you've played in the past, and you have the mobile security key attached to your account, you can continue using it even after going free-to-play/preferred. You can't, however, attach a new one to your account if you're free-to-play/preferred. If you have the physical key fob thing, nothing changes. You can continue using it, and if you're a new player, buying it on the web store will also give you preferred status since it's 5 bucks. It's been said that attaching a new one will not be available at day one of free-to-play launch, however.
If I'm currently subscribed, or have in the past, or do in the future, what do I lose/keep if I switch (back) to Free To Play?
Look over the free-to-play limitations, add in the preferred status perks (since if you've ever subscribed, you'll only ever get bumped down to preferred, not free-to-play), and that's what you'll have. Some things are slightly more complicated, though.
If you've created more than 2 characters, you'll still have access to them all (regardless of whether they're free-to-play races or not) at the start of free-to-play launch. If you delete any, however, you cannot create more until you have one or less characters. Notice I said, "at the start of free-to-play launch"? In a patch soon (how soon, they have not said) after it launches, you'll have to choose which 2 will be your active ones. It is unknown at this time if you'll ever be able to change your active characters, or if there will be a cooldown on how often you can change them if so.
Any artifact (purple) gear you have that is bound to you is still able to be equipped, though any future drops will require the one-time artifact gear authorization. Any extra cargo hold tabs or inventory expansions you previously purchased will be kept. Legacy unlocks and perks (including species unlocks) will be kept.
So what are these cartel coins?
These are the currency used for the cash shop; think microsoft points. If you're a current subscriber, you'll be granted some at the launch of free-to-play (http://www.swtor.com/free
shows how much for what, and http://www.swtor.com/user/cartelcoins
shows how much you, personally, will get). You'll be able to buy them on the SWTOR store, though currently it is unknown how much they will actually cost.
So this cartel market. What can you buy on there?
You can buy a handful of one-time authorizations or weekly passes. At max level and want better gear? Get the artifact gear authorization and you'll be able to equip purple quality gear from that point on. Only really care about warzones? Buy a pass for unlimited warzones for a week. You'll be able to use your cartel coins to upgrade your inventory/add extra cargo hold tabs (it is not advised to buy the base cargo hold access, since any purchase of $5 or more will give you preferred status, and thus automatic cargo hold access). Even as a subscriber some of these have value, since inventory upgrades (and most of the one-time authorizations if you ever want to go F2P for a while) have the option to be account wide. They're usually a little over double the cost of the per-character cost, and apply to your entire account: even characters you make on other servers will have them.
There are also consumables like temporary XP and Valor boosts, Fleet Passes, and medical probes (for in the field revives). There are sets of level 31 artifact (purple quality) armor, and level 15 and 43 single chest pieces. They're about the same quality as equivalent level artifact drops you might find rarely on enemies, but the main draw is that they are adaptive, which means the amount of armor matches the highest type of armor you can equip and everyone can equip them, opening up cosmetic choices that were previously only available to certain classes.
One of the main draws will be the vanity items, such as unique speeders, vanity pets, and toys (like the carbonite chamber or rancor holo-replica). Additionally, there will be cartel packs for sale, which can contain items only found in the packs. For example, the Crime Lord's Cartel Pack contains: two rare bonus items with a chance of a super rare, one XP or social point boost consumable, one type of crafting material (how much I got seemed to depend on the quality: 10-20 for blue, 5 or so for purples), and one companion gift. The rare/super rare items can be mounts, vanity pets, empty adaptive armor, or toys like the sith meditation throne, etc. If you want these items but don't want to spend money/cartel coins to get them, don't despair! Whenever an item is bought on the market or found in the cartel packs, it has a cooldown during which it is bound to that person; after the cooldown is over (which is 3 days for free-to-play players and 2 days for subscribers), the item can then be sold on the galactic trade network or traded to other players.