Well, now I'm in the 3rd playthrough.
to describe the 'dual weapons' @Darcnova,
it really isn't dual wielding per say. its more of a single weapon that is equipped in the weapons point and it appears to be two swords. Thats the only dual weapon there is.
Yes, you have to buy the CG's, although not with money but with the [P Points]. However there are a few things;
1. The CG's can only be bought through the Mugen Field, which has only allows a certain amount of CG's per shop/floor. This means people are going to have to grind through the floors until they reached that one floor. (A shop is on 10F, 30F, 60F I haven't gotten past that point) Players are going to have to grind all the way to the next shop if they wish to unlock more CG's.
2. CG's can only be viewed if the player has pass the event. Even if you managed to grind all the way to the 60F and buy the pic's they won't pop up until you see them in Story.
3. They are expensive as heck. First batch is around 1000 or so (Not too bad if you remain grinding in one of the worlds.) Second batch is around 5000 (The last world can get you the points needed) Third batch, holy hell is around 50,000 to 100,000 (You'll need to farm points allot within the last world if you want them)
4. ALL CG's are locked, non-ecchi included, until you buy them.
Also [P Points] are used to up the limits on your chara lvl. (Basically the limit is 100 at start, but you can put the points to have them increase the limits. Among other things like (Generic soldiers, the strength of Mugen Field - having this will increase the enemy's lvl's in MF but also increase the experance, increase damage limit, etc.)