as for your charging check all your fuses, both alternator wires, if there is a break in the circuit most alternator test will say its bad, usually it will say its putting off 0 volts which kinda hard to believe since you would have had problems long before then... and make sure you got good clean battery terminals. also get a electrical meter and check for 12volts while its running. somtimes low power can cause the car to be harder to start when hot.
For the speaker noise does it increase with engine rpm? if so is your stereo aftermarket? running speaker wires beside a power wire for a amp will make that noise.. for the stock system there is a little black box, very small beside the ignition coil with 2 wires running from it, make sure they are both plugged up because they come unplugged easy, its there to stop that noise.
for the starting problem.. next time it does it try giving it a jump, possibly you could have a poor connection somewhere. When you try to start it does the engine crank over or does nothing happen at all? turn the key off then to the on position and listen for a wirring sound, if you hear that your main relay and fuel pump is working.
and for the oil.. go ghetto department store and get 2 or 3 cans of gunk engine brite (not the foaming type) and cover your distributor and with the engine cold spray it all over the engine, let it sit for 15 mins and wash it off with a hose. let the car idle untill the oil starts to leak, DONT DRIVE IT, or else you wont have a clue to as where it came from because it will blow everywhere. fresh oil will usually be a little hard to spot since its still clean, press a napkin against all gasket mating surfaces after the engine has dried. make sure to get under the car around that oil pan too.