Class Trees

[Kiarin]

Methinks the more the merrier :-). If there could be 100 tier talents' tree, I personally would welcome it.

But this is 1) exponentially harder for devs to invent, imply, and most importantly - balance,
and 2) exponentially harder for players to sort out.

So as a golden mean, maybe, starting from lvl 50 and then every 5 levels. This way, a tree will have 7 tiers. And, let's say, 3 talents to choose one on each tier. This means 21 talents to invent for each class - more or less reasonable. And a plenty of freedom to customize your build.
This is, however, totally debatable. For example, if talents would have grades (!), there could be significantly less of them.