Need help with some major overhaul Noob status

[SFGS500]

Hey guys, just bought an 89 GS500 for dirt cheap. Had an amateur mechanic give it the old once over, installed new tires, lubed chain and replaced fork seals. Now I'm on my own and I have some serious issues that need to be addressed.

1) Carbs need rebuild. Bought two rebuild kits with gaskets and O-rings just need some tips/tricks/suggestions on going about it.
2) Clutch is slipping under load. Above 5k with throttle the engine revs but the bike doesnt accelerate. Do I need to rebuild the clutch? Is this a mere adjustment? If I need a rebuild, do I need new springs? Friction plates? Steel plates?
3) When the engine is hot, the idle sits at about 4k when im stopped at stop lights etc. If i adjust the idle down, it will bog down too low and die 1 out of 5 stops. Will this be remedied by a carb rebuild? Is this something more serious like a vacuum leak?
4) Previous owner did an absolute hack job at wiring an aftermarket head light. I was able to replace a lot of the connections and get all the lighting to work properly. Is it normal for the right side turn signals to be dependent on the headlight being plugged in? Not that I would ever ride without a headlight plugged in but just curious if this is normal or due to the PO's negligence.
5) Another wiring issue/interest. Under the seat attached to the frame is a small wired switch. I did not know what it was so I pressed it while fixing the wiring. When I started the bike, it warmed up as per usual but when I put it in gear, it would instantly kill the engine. It would start up again no problem but again, putting the bike in gear killed the engine. After a small freak out, I remembered the under seat switch. I released it and behold, she went into gear without hassle. Now the apparent age and condition of the switch worries me that it will not hold its place and could 'pop' into action and kill my engine if I hit bumps etc. Great for deterring thieves I guess but pretty unnecessary for me. Should I get rid of it? Replace it with a sturdy new switch? Anyone else seen something like this on a GS?

With all things considered and me being a C+ mechanic with a decent tool set on a budget, should i save my pennies and give a local mechanic my left nut for piece of mind or should I get intimate and goes balls deep into my beloved new GS? Should I tackle each issue one at a time and dedicate two days to knocking it all out at once?

Thanks a lot for any input and I look forward to hearing back from you.

[adidasguy]

Get a Haynes or Clymer manual. One thing they have in addition to all the technical stiff is the wiring diagram.
Everything should be in the manual, but as added info:

1: Youtube videos will show you
2: Start with a 3 point adjustment. On the gstwins WIKI and the manual
3: Possibly air leaks or valves need adjusting.
4: Turn signals independent of headlight. Follow the wiring diagram and put everything back the way it should be.
5: Seems like someone hacked the side stand switch. If side stand down, bike will die when you put into gear. That switch you play with sounds like the side stand switch. Side stand switch pressed IN closes it and bike will run in gear. If on the side stand, it is closed when the side stand is up. Manual will show where that is.