Welcome to the best owners club.....
Check your alternator by putting a voltmeter accross the battery terminals.
Run the engine at about 1500 rpm minimum, turn on the heated rear screen, headlights etc., to put a 'load' on the alternator.
Voltmeter must read 13 to 14 volts to prove alternator 'keeping up with demand'
If not, alternator problem, assuming the battery is good,how old is it?
Misfire could be plugs, leads, distributors, etc.an assortment
What plugs did you fit?
Cannot help with remote, my remote key was missing when I got the car, still getting around to it..........