A Trap-focused character works very well in theory (at least in 2.0), but lacks practicality for most situations.
As discussed above, you're incredibly deadly to just about everything if you have ample setup time and can lure or otherwise force the target(s) into your traps, and being able to use Trap Globes is a nice way of assisting on the battlefield (they use the Elemental qualifier, so very little is going to resist more than one if the creature is vulnerable to the effect you're throwing at it in the first place). Your sleeping quarters and storage is also very well protected, if only by the idea that a wrong step into your bunk could blow everything up.
It also has a lot of glaring drawbacks, primarily that required setup. Outside of battles you're aware of and can prepare for, you have very limited ability to actually contribute to a skirmish; setting traps on the fly is prone to interruption, and you may catch yourself or allies in a blast and make them easy pickings for whatever you're fighting. If you're travelling to a battle (which, at least in our chapter, is basically every single time you go on a mod), you have either a) no time to set anything up, or b) no space to set anything up; you can't set traps ahead of time (because they technically wouldn't "be there"), and it's unreasonable to expect or demand that the rest of your group hold off the enemy while you get set up.
If you want to be a "Trap Master", your best bet is to get enough ranks of Create Trap to be able to make whatever traps you want, then invest heavily in either Alchemy (Gas traps) or Create Scroll (Scroll traps), and supplement all that with Stealth skills (Evade/Dodge, Doom Blow, etc.). Weapon choice makes little difference at this point, since your primary offense is going to be Gas Globes/Scrolls and Trap Globes, but Staff is cheap and not a bad choice (you can block with only one hand while chucking Globes), and Archery will keep you at a distance (but it requires two hands to use a bow/crossbow, so switching between arrows/bolts and Globes could prove more difficult that it's worth). Alchemy counts towards your Stealth Skill XP, and Scrolls pretty much require two hands, so take that into consideration when deciding how to supplement your traps.