RE: Bottoming out...
Definitely do not set the truck up to purposely bottom out. That makes for a very inconsistent handling truck. I doubt the shock caps will blow out, that would take a very hard landing. I have never blown shock caps.
I race weekly and I know of no one who sets their truck up to bottom out. As matter of fact, we tune 'pack' at the lowest setting for jumps.
Although, a truck set up with minimal pack will handle the best. Pack should be *just enough* to not bottom out. Too much pack will cause the truck to lose traction.
Do you know how to tune for pack? You have to use shock pistons. If you are Associated, they are numbered from 1-3 and Losi uses from 54-60. I can tune pack just by looking at a picture from a track, but what you can do is try them all out and see which works the best. In my experience, Associated 1 and Losi 54 are for very smooth tracks with very small jumps. Associated 2 and Losi 55 and 56 are for most tracks and Associated 3 and Losi 57 are for poorly built tracks with no landings. You can also try drilling out losi 60 for very smooth tracks.
Another thing that affects shock absorption is droop. Don't run too much droop if there are big jumps because they shock travel length just won't be enough.
The perfect shock setup which isn't very hard to tune for is to adjust shock movement to where the truck lands, then bounces up to just about the ride height. If it takes too long for the truck to rebound but the pack is just right for the jump, then go up one in spring weight. If the truck bounces too much but the pack is just right, then go lower in spring.