I believe there's a charger for the iPad that puts out 2 amps. Would this be any problem for the Evo? Just a faster charge?
Yes there would be a problem.
The EVO's charging circuits are rated to handle only 1 amp, and this is also likely limited by the battery's ability to charge as well.
Best case scenario would be as you describe, but in reality any of the following are more likely to happen:
1. It fries your EVO's charging circuits, and your EVO no longer charges.
2. It fries your EVO's battery. (The circuits SHOULD stop this, but it's possible if the current is simply too much for them to handle. Think what happens during a lightning strike)
3. The charging circuits only draw 1amp despite it being a 2amp charger. Everything works fine, although the charger is less efficient.
4. Nothing happens, it refuses to charge.
All in all, not a risk you want to take.