Using stored energy (springs etc.) not to climb the pole.

We know that we cannot use springs or elastic bands to climb up the pole but can we use those for other purposes (to hold the pole) on our MiniBot ? Also how are we going turn on our MiniBot autonomously in the last 20 seconds ? Should we use a standart FLL NXT as a processor for our MiniBot ?

Springs are not legal as they are not listed in the allowable parts in <R92>. Surgical tubing is listed in <R92> and would be legal to use for the purposes you describe.

The lightest way to control the Minibot would be a motor control circuit using light switches or limit switches and triggered by either your deployment mechanism or the pole and turned off by the target. It is legal to use the NXT for control, but it will be much heavier.