I would be more concerned about crash damage than the clicking sidestand relay and funky neutral light.
The sidestand relay will do that from simple battery failure. Clicking happens when the relay energizes, causing current to flow; current flow makes the anemic battery drop voltage low enough to releases the relay. Once the relay is released, battery voltage comes back up, energizing the relay again. Cycle repeats a couple times a second. The neutral light blinks each time voltage drops out.
Why the relay has power with the key OFF, I don't know, but should not be hard to trace down.
If crash damage is minor, and it is a smokin deal, buy it!
The spade connector on the main ground wire connection from the battery was corroded and making a bad connection, causing weird electrical stuff. And the kickstand switch was bad. That's the only real issues, but I also had to fix a lot of stuff due to the last owner trying to "fix" things. The tip-over sensor wiring was cut, the rear brake light wiring was cut, the battery was dead, the battery cable bolts didn't have any nuts to screw into, the main ground was disconnected, the countershaft sprocket nut is missing!?!
Transmission is fine, the "transmission issues" mentioned were because the countershaft sprocket was installed backwards and did not have a nut on it. When he mentioned gears not in place I thought he was referring to the stack inside the transmission...After taking off the sprocket cover a lot of head scratching ensued. I'm still not sure why half of these things were messed with.