common problem?

[jeradsvx]

Just a few questions to ask,
was wondering if the valve cover gaskets leaking are a common problem. Mine seem to have a small leak.
Also when i turn on my headlight, on the dash lights you can see a pulsing, bright then dim, bright then dim, under the impression that it is the alternator, the alternator is less then 10k old from last owner
Also while I am here something weird happened today, started the car, rpms went to 500 and wouldnt go higher, soon as i touched the gas the car would stall....did this a few times and finally i let it sit at 500rpms for a little while and pressed the gas and it didnt stall, acted weak but didnt stall.
any ideas would be appreciated.
thanks all
Jerad