On your wiper issue. I had similar issues. I was to the point, when it wasn't workin properly, I would give the wiper motor a couple pops w/a screw driver handle. It would go, sometimes w/no issues for awhile. It was getting worse. After a bit of reading up on it after taking apart, cleaning an grease what looked lubed at 1 time. My conclusion was a bad spot on the armature. Replaced the motor. No more issues.
On your light issues, sounds like bad ground somewhere. Do you know how to use a Multimeter?