Well, from what you asked, only the leveling system is possible for the player, but as long as i know, the palyer won't be able to choose wich atribute to level up (strengh, agility, etc.).
Huge worls aren't supported right now (you can make nice big open worlds, but not 2 big).
You can have a map, but you can't interact with it, until the source code is tweaked (so, no selection of the maps).
There isn't a level foward-back function yet, this means that you can go lv1, lv2, lv3, lv4, lv5, etc., you can't jump levels. But it's possible that this function comes in the next update, lets just wait.
But let me say this: RPGs aren't only big open worlds and free roaming games, there are lot's of rpgs wich are strait foawrd level games. Have you played Dark Messiah? (just a small, latest hit rpg game exemple), It only has 1 or 2 places wich you can actually go back levels, no where else, also, the leveling system is pretty much simple, and the levels are small like hell (but they do have great decorations
).
If you're really looking to make a "complicated" FPS-style rpg, i suggest you go with DBp, and get help with the coding (buying 1 of the books it's a start).
Anyway, good luck.
My love is seperated in 2 parts, 1 of them is 3ds Max 7, the other; FPSC.