Just to add to the backfiring list of items, if your exhaust is too free flowing such as an open pipe you can get back fire. If a float is sticking in a carb you can get back fire and engine miss.In this case the faulty carb often overflows during idle and you may see gas dripping on the ground. Same if an enrichment valve is stuck (often refered to as the choke). A malfunctioning carb can cause a misfire that can make you think its electrical and a bike that has sat for a long time without running can often result in carb issues.
A coil that is working hit and miss can cause a cylinder misfire but gas still goes through the cylinder when the raw gas hits a enough exhaust temp in the exhaust pipe it can cause a backfire. A simple thing to check over is all the primary wiring for your ignition if the bike sees enough wet weather, you may need to open and clean all your connections. I once thought I needed to replace my ignition module but when I took it out and saw all the green I cleaned it, put it all back together and the bike has run like a dream Plugs are a cheap investment and try running the bike in total darkness to see if you can spot any arcing from the plug wires or boots. look while everyrthing is dry 1st than do it again whil spraying a mist of water all over the plug wires.
Your handling issue sounds like tires, they may be out of balance or just sat for so long that they developed flat spots and with age the rubber gets harder and less able to return to its proper shape.
Once you get the bugs out of it you will have one awsome bike.