I'm new also, but I'll give you my five bucks..
1) Refer to an electrician (having said that) Capping the insulated wires and removing the bare should make it ok.

2) What were the breakers there for? Is there switch/receptical not functional in the house? - Seems suspicious - abandoned wires and breakers - may be a dead outlet somewhere. Otherwise - no problem.

3) Wires shouldn't run across the buss.

The missing knockout and while they're there - remove the wire nuts --hmmm maybe they could use those for something........

Jimmy