Sounds like the dirt may be trying to clog the main jets too. Get your carbs cleaned & fit a fuel filter & should stop the problem. Also check the diaphragms in the carbs just in case they may be holed.
Sounds like you bought some dirty petrol (gas) & the dirt has clogged the idle jets in the carbs. Get the idle jets cleaned & it usually sorts the problem.
Try checking the brushes. If they're worn past the mark on them, then you'll get no charge(by the way the colour is ok, it's what the stator gets covered in to protect the copper wire). I had a similar problem on My FZ600 & a XJ550.
The bracket you're talking about may not be damaged, the foot peg may have just rattled loose. You can tighten it by removing the bracket from the bike & tighten the allen bolt that passes through the back of the plate & holds the pedal & peg together (be careful as you may need to unhook the rear of the pedal from the rear master cylinder). Oh yea you might as well grease between the peg & pedal to make sure it works freely before tightening the bolt.
Hope this helps.
I have a 86 fz600 with k&n cone filters & can say that if you change to them up your jets by 2 sizes to stop overheating (too lean mixture), by the way the bike will have starting/running problems in wet weather til the bikes warms up & dries the filters.
vintagephil check your idle jets as what you're describing is classic blocked idle jets & airways.
junker check your ignition switch coz i had the same thing & after a 5 mile push 2 a regular tea stall i go to (high beech) a friend told me about the ignition switches on these models & for some reason the backs tend to work loose giving a intermittent electrical supply. tighten the screws on the back of it or replace the switch will solve the problem.