for the power window switches take them out and clean them. they are very easy to take apart, 4 little clips hold the bottom on. pull the bulbs off, and use a fine wire brush and some contact cleaner or whatever works for you. that should solve that problem.
for the door lights, there is a contact switch. most likely you are having the same issue with this, the contacts are dirty and corroded and not making a proper connection.
the power locks could be the same i guess, just check all the connections.