A) For the bronze award, you only have to get at least one bot across the ravine. For silver, all your bots have to end up back on the left side of the ravine. For gold, all your bots must end up on top. Any bots dying, or falling in the pit, mean faliure for all the awards
B and C) You can have as much energy, body etc. as you want. Infinite energy can be supplied by setting the age cost to -32000
I've already built a bot that gets across (which means I'd get the bronze), and attempts (but fails) to bring the cyan bot back.
I suppose, since this is the first challenge, a hint is in order ...
What it does is build a line of fixed, tied bots in an incline by reproducing upwards and right. These then unfix and expand the ties to just under snapping limit to shoot out the chain and bridge the ravine. The lead bot then ties to the cyan bot, and all the chain then contracts their ties to get back. It's a whiplike motion, like a cobra. Only problem is it's hard to change the tie angles without them snapping, and the whole structure just falls slightly short on the recoil phase and snaps into the pit.
I'm sure there's more solutions. It's not impossible, just incredibly frustrating