The more you expand, the harder it would be to use individual skills. The jack-of-all trades versus the specialist type deal. Yes, magic will expand your ability to adapt to situations, however, on the reverse side, if you only have one or two skills upgraded, you will be very strong in those areas, but very limited.
For example, you could pour everything into say... healing magic. You would be the teams best healer, by far. At the same time, you would be squishy as fuck and easy to kill because you would lack any armor skills, weapon skills, or defensive training. At the same time, you could put a few points into every skill. Yes, you would be able to do everything that came up, but you wouldn't do it well, or even close to as well as anyone else. My suggestion would be to find a 'role' you want to fill, and advance in skills useful to that role.
The experience for posting will be evened out by participation in events. I realize everyone cannot be on all the time, but I do want them to feel a difference if you say... post once every other day, rather than 2-3 times a day. And, no matter what your level, more people means fights and such are easier. I may simply make it so that after x posts per day you stop gaining exp, or something of the like.
Its an rp, so its a sandbox, but I hope to see most of you stick together, because that makes it much easier on me. We will start on day one, with the announcement that it is a death game.