Laser cutting for dummies? Questions for those using it already.

[Cypher226]

I'm in the middle of building a modern/near future gaming table (it's stuck in development hell at the moment) and I've come to the realisation that I need to design my own stuff to get the look I want - most of the laser-cut stuff readily available is either too olde-worlde (Sarissa, 4Ground, Sally 4th), too expensive to ship in (GameCraft, Burn-In Designs, CorSec) or too far future (Sarissa again and most of the stuff aimed at the Infinity market).
Essentially what I'm after is modern building styles - just shells really as the main structures are the parts I hate building  - particularly at least one style of stereotypical US suburban house, a strip-mall type set up and a run of storefronts. Maybe some signage and fencing. In short, stuff for US invaded a la the more recent Call of Duty games and more urban X-Com settings. 

With this in mind, and the acquistion of a new (old) laptop from my good wife (she needed a better one to play The Sims and Civilisation 5 on - the horror :p), I've been mulling over how I can get the look I want and have come up with some questions from the quick reseach I've done....

I understand most laser cutters can work from Vector artwork (through a CAD or other drawing program)?

So I could design in Inkscape - 'cos it's free and I don't want to pay silly money for something I'm not planning on using that much - and then work with a willing/able manufacturer to get the cutting done?
Are there any particular tricks/techniques that have to be observed when preparing files for laser cutters?
What kind of tolerances do you look for/build in to cuts?

Of course, if it works out well, I might be looking to buy my own machine in the future - but that would be a long way off!

Cheers for any advice chaps!