Some limitations on the free-play:
1) You can't fly anywhere and you can't walk out from T1 Empire-Chaos pairing, so no access to the AH or bank or the other pairings
2) Can't send mail through the postal system (but you can recieve)
3) You can't use the new PvP rewards introduced in 1.3.4, but that is realy not of concern as those are only sold in Altdorf (where you can't get to)
4) You can reach level 10, so you will never be able to get a hat or helmet (apparently the lowest level you can get a helmet is at 11). Cloaks and shoulders are rare, and they are bought and sold for outrageous money (the froobs (if an AO acronym is allowed here) have nothing to burn their money on after they've bought the "basic" PvP rewards, so money just keeps on stacking).
There is usually war going on in the T1 PvP lake. I've logged on early in the morning, during the day and in the middle of the night, and there is always fighting going on. During peak hours there can be several raids going on at the same time, and the fights are truly epic.
Of the scenarios only Gates of Ekrun and Nordenwatch are left in T1. During weekends there is also a special sceanrio, which can be one of the "shafted" scenarios (like Altar of Khaine, Phoenix gate etc etc) or one of the "holiday" scenarios (like the ironclad (where an orc ship crashes into an ironclad, and there is a fight over the control of the ironclad) or gun factory etc). Scenarios are not that popular anymore it seems, as even during peak hours there is a couple minutes queue. Then again, the open PvP lakes were always where the fun in WAR was