1) You cant wear any new artifice (purple) gear, although you could still wear every artifice gear which you've used during your sub time and is bound to you.
2) Any credits over the 350K limit will transfer to an escrow account. you could buy unlocks from cartel market to transfer credits from you escrow account to your main account.
3) You couldn't participate in operations anymore, although you could buy weekly unlocks from cartel market.
4) You could participate in flash points without any limitation, but the loot of the final boss is limited to 3 FP per week. There is no limit for the loot of the 1st & 2nd boss.
5) Your quick bars will be limited to 4, instead of 6 for subs. This not a big deal since the game is totally playable with 4.
6) You couldn't use hide helmet and unified colors for the appearance of your characters.
7) You will no longer be able to use titles and legacy titles for your characters.
8) You will be limited to 6 character per server. any additional character will be inactive. You could choose to inactivate which character.
9) Your crew skills will be limited to 2. You can choose to inactivate which crew skill.
10) You will not have access to "Section X", which is necessary if you want to acquire HK-51 as a companion.
That's all I can remember from my personal experience, there are some restrictions for pvp players which I don't know since I'm not a pvp player.
