Light switch or Turn signal switch?
 

So I have searched through several pages on this topic but found none that helps with my specific problem.

Here's my problem:
Exterior-
Running taillights not working- they should be on when I turn on my headlights but they don't. (Replaced both bulbs and clean connection)
Licence plate light not working. (Replaced bulb and clean connection)
Front passenger turn signal not working (but have not replaced bulb in all fairness)
Parking lights not working (changes bulbs and cleaned connections)
Third Brake light not working. I'd figure I'd just replace it but not till I can fix these other issues, cause there maybe a chance that its fine.

Interior-
Complete dash cluster not lighting up, in fact nothing except the radio lights up. The cluster gauges fine by the way.

I have checked all fuses and I'm running out of ideas. Is it possible that all these are related? Could it just be the master switch for the lights?
Also, my turn signals just started to turn solid in both directions and when I engage the battery without turning on the engine the buzzing noise seems to die the longer I keep it on.

Everything else works fine, just not the items listed above. Any ideas or suggestions would be greatly appreciated.
Thanks

95' Chevy Blazer 4x4 4door LS