So right now every one wants a werewolf tree and a vampire tree amounst other trees svck as spears and crossbows, but the only problem is... what about your characters that you have spent hours and hours appon? all your points will be in other trees... so what do you do?

Simple. They increase the level cap every time they add a new skill tree.

They could add 10 levels per skill tree, as each tree would have a max skill of 100, and you level up every ten points in the tree. Then you end up with 10 skill points per expansion that adds a new tree!

That's an easy one. On the main menu there's this option called "new." I find this solves this issue quite well.