I was thinking of making a rogue/caster mutliclass...mostly likely a rogue/wizard who is a trapmonkey and uses repeating crossbows. So far the build looks as follows...

Dwarf
strength-10
dexterity-16
constitution-12
intelligence-18
wisdom-8
charisma-8

How is this build so far?
Should I splash a 3rd class in there?
How many levels of each class should I take?

Thanks in advance