The black box is your CDI and the silver box is a voltage regulator and has a ground coming off of it did you disconnect the ground? That my be your prob
Sorry i've kinda edited my reply as i thought of things, but my thought about the press putting the bearings in are if you got them in, you can get them out. But you'll never in the future be like, hmmm i need to replace my swingarm bearings.
The Pivot bearings are suppose to be like that the last swingarm i got i had to get a piece of wood and gently press it in place with a hammer. The first swingarm i got was crazy tight i thought i was gonna break the bearing putting it in. What kind of swingarm is it cause Tyson racings swingers for some reason are like that. I'm sure you have common sense and know that if you powdercoat your arm not to get powdercoat where the pivot bearings go. I wouldn't worry about it to much since you have number one the swingarm then the bearings then the pivot rod and theeeeeeeeeeen the swingarm bolt. Just make sure you grease everything up before installing it and it will break in and work out itself were only talking about a few inches of movement and not much wear and tear.
Sorry forgot to say if you ever have to replace them than the best bet is to press them out and replace them don't reuse them. The concept of everything being tight should be good cause you don't want ANY movement at all.
I got my plastics painted about 3-4 months ago and still haven't put a coat on mine yet but i haven't been riding mine it just sits in the garage for now until i ever get my damn motor back