No; you had two questions and I couldn't answer the first. Poor choice of words on my part.
There are two ways to add characters to your party. One is by talking to the four people hanging around various areas near the first city. Three are in the city, one a bit outside. the other way is to pay a merchant of sorts at the end of time/home world for a mercenary. The mercenaries start the same regardless but if you choose say two of the original talk-to characters and later go back and choose one of the other two, that one will have accumulated EPs that you can then disperse to build up the character like he was with you the whole time.
I don't want to spoil things but, then again, this will happen regardless. There are two ways to "find" the "end of time" both in the initial city. The first one of the two that you do will immediately whisk you there. In that place, as the game progresses, you will unlock rooms. In one of those rooms, you can hire mercenaries (but still have a total of four in your party). Oh, and don't worry - once there, you can come and go as you please easily and quickly so you don't have to complete a bunch of stuff first.
