you are overwhelmed by the forest......you need to concentrate on the trees...one at a time.
- your horn wire is grounded. start at the horn and work your way back to the switch on the left hand control until you find the ground. most often, you will find a pinched wire at the hand controls.
- your brake light it probably on due to a problem with the front brake switch. it is not uncommon for the actuator to break off, causing the brake lamp to be on all the time. regardless......find he brake light relay under the seat and determine what is causing it to pick up.
- reconnect the turn signals.
- the cold start issue is a symptom of a problem with the cold start air/fuel mixture. your engine needs only 3 things to start and run: spark (as in timed ignition), fuel (as in a proper air/fuel mixture from the carburetor) and compression. if you have cold start issues, you either have an incorrect air/fuel mixture or low compression. a compression test will identify which it is. a lean air/fuel mixture can cause starting issues. leaking intake seals are the most common cause of intake leaks.
- the correct cold start procedure is to turn on the fuel, pull the enrichener knob full out, set the run/stop switch to run, turn the ignition switch to ignition, twist the throttle grip full open a time or two, release the throttle grip and press the start button. after the engine starts, allow it to warm for up to about 30 seconds and ride. adjust the enrichener knob to maintain idle rpm as necessary for up to about 10 miles of riding, then ensure it is fully in (off). never warm the engine on the side stand.
- if your circuit breakers were grounded, nothing would function on the bike and the breakers would constantly"click" off,, then back on and immediately, click off and then reset back on and.........etc, etc, etc. since you didn't say the breakers were tripping off, I can only assume they are not grounded. again.....the inherent issues with using a test lamp instead of a proper multimeter.