There's not too much dead time, the only problem is when a single player is taking a long time to program his robot. It can be mentally taxing, I don't find it too much of a problem but every now and again (especially when riding convey belts) it can be highly frustrating as you swear that you can land on a flag but always seem to just miss it.

The basic game is quite straightforward with very few rules questions all of which are in the rulebook if you read carefully. The expansions all seem to add situations where there is no correct, logical solution, only rulings which will need to be explained. I won't play the game with these. I think the basic game has more than enough tricks to cause you problems. Every other player (except my group thankfully) seems to disagree with this so your mileage may vary.

I'd recommend that when you first try it out that you be careful about the board layout. Use 1 or 2 boards max (the simpler ones at that) and 3 flags. It's quite easy to make the game a 4-5-? hour beast with what appears to be a moderate board setup. Starting out simpler (and possibly playing multiple games) will build up interest much better than being hopelessly behind in a marathon session. Also, I'd forget the limitations on deaths. Let everyone die as often as they like!