If you program the AI to use varying lines, you'll be able to 'find grip' elsewhere. Marbles form off line though so if a line is used by most of the AI it could ruin other parts of the track. I don't know the answer to your second one. I heard mention of programmable timers, triggers, etc in tracks, but I don't know how far they got/will get with that. Infact Scott may have mentioned it in his recently track update?