Sounds like you're fighting multiple issues.
1.) The headlight one is likely to be worn wires or exposed terminals. I would pay particular attention to the white wire that leads from the control to the low beam on the headlight.
2.) Have you read out the primary resistance on the new ignition coil? Sounds like it might be too low.
3.) Any wires that were smoking will need to be replaced. Even if they're functioning now, the copper will have gotten brittle from the heat and will need to come out.
4.) As a corollary, check your main fuse and be sure it's no bigger than 15 amp. The fuse should have blown during many of the instances you're describing above.