Yes, how many miles???
I think I would just replace the bearing and any worn transmission parts, the top end of these motors lasts a long time.
I used regular ultra black permatex sealant on many motors, no leaks.
Replacing seals is likely a good idea if the bike has miles on it, allthough Japanese bikes tend to not leak much.
For clean up, I often use HOT water and soap, then dry, wd40, oil, and put in plastic zip bags.
Kerosene also works well for clean up.
Red or green locktite is going to hold any nut or bolt, inside the motor or out.
Green (stud and bearing mount) is just one step below welding, and its not coming apart without a fight!
Some bikes have heat treated parts which makes them look like something got hot.
DR650's do not tend to get hot...