Hi Clinton, Glad I might be able to help.
1. No cooling oil weeps out through the wiring slot. Nothing I've noticed. Silicone sealant seems to work fine there, or some sikaflex, but don't use too much sika since it bonds so strongly. Oil weeps between the inner bearing race and the axle. Then eventually past the outer seal. It's barely noticeable. Pre ride give the inside of your rear rotor a rag wipe, and maybe a spray of brake cleaner first. Then before hitting a track section requiring heavy braking, be sure to use the rear brake and heat clean the rotor and pads. On the sprocket side, it's no problem at all. You might intensionally pump 100x as much oil into your freewheel ratchet to lube it.
While your side covers are off, you should consider getting some 1x1mm groove rings machined into them to greatly increase the surface area and heat dissipation. That's what I'm going to do with my next hub. Just for the longevity of the next motor. With this oil cooled motor, I can ride it pretty hard and get the hub temp up to about 80% on the bar graph, then it seems to hold no matter what I do. Prior to my oil stator cooling, reaching that temp meant my ride was effectively over within the next 5 minutes. IE. Heat alarm and DC-1 throttle limiting. Had to also be bad for the stator life.
2. Yes some oil weeps out my 1mm breather hole. You could make it 0.5mm. It's only a pressure balancer. Not an issue. Drill it near the sprocket. I suggest you use a dremel for drilling with bits smaller than 1mm.
3. Yes the Tubliss liner greatly reduces the chance of a sidewall pinch. A rock would have to push directly into one rim edge. Keep in mind that a sidewall pinch is no big deal when there is no inner tube to get pinched inside the tire. Since the sidewall is maybe 10x tougher than any inner tube. Also if the outer tire was ruptured, you simply ride home on the outer flat. No problems, since the inner liner keeps the bead in place and rim off the ground. Just ride a bit slower to prevent overheating the tire sidewalls from over flexing.
Regarding the full width throttle, I broke my Crystalyte wide throttle in a crash. Just turned the throttle open too far and stripped the inside lugs off. So I ended up extending my stock 1/4 width throttle in much the same way that you did. It's easy to trim down the remaining fixed grip to have that little section on the end.
Regarding my trimmed bars. I started with 6mm off each end, then went to 12mm. This feels very different. With shorter bars it way better through the trees! But you do need good fork function, else the bars might get ripped out of your hands over rough fast sections. Surprising how sensitive it is.
Here you can see my hub. The M4 bolts with fiber washers are the fill/drain holes. You cannot see the breather in that pic. I notice my scuff pad is out of position on my swing arm. My rear heel pushes on the swing arm a lot.
My rear wheel+tire is so good that I'm now again feeling to need to revalve my forks and shock. My shock needs firmer high speed comp damping again (3rd time into it). My forks I'm not sure what's wrong ... Having only one clicker for reb and camp damping bleed control makes it difficult to isolate what's going on. They are a lot better than the R1s. The R1s would have put me in hospital many times if I asked them to do what my curent forks can do. But for sure my modded DNMs can be better. I'm going to have do have some guesses.
I've got some shorter 155mm cranks coming next week. I expect shorter cranks are going to transform my bike into something much better. Not just better for ground clearance when pedalling to boost up a rough steep hill, but when standing on one leg around a tight fast corner and the outside pedal is down, it sucks when the crank end clips a fixed rock. 15mm less per leg will be great.
I suppose I should cut off that metal bracket on the swingarm under the rear sprocket. It's just dead weight, and I'm never going to fit rear chain gears to this bike, or care about resale value.