A.I've done that archway type thing, I'm at school, so I will explain the best I can:
1. Make a brush like a door, archway, whatever you want. Do add special so it's placed in the world. Now, resize the brush and subtract it within the original brush, making an arched effect.
2. Now, I would reset brush properties, go back with the primitive square and resize to fit over the whole archway. Intersect and it "should" intersect the archway, the outline border and inside, not the whole thing.
3. Just copy polys to brush, go and add special and it is an arch! /~unreal/ubb/html/smile.gif
B.Those pads that throw you into the air are jump pads. They are scripts which do exactly what they say. Just download it from somewhere, or get it from another map set, and put it into your Unreal\System directory and you're set to go. If you do all this, to use it, I believe its under, Class, Navigation Point. I'm not sure which one, but its there.
Jenkins