Amount of oil varies depending on your cooler(s), oil filter size, length of lines, etc.
I recommend the oil level be at the lower of the 2 marks on the sight glass while the engine is running, or about 1/3 of the way up.
As for oil filters, I run WIX 51085, just a personal choice. make sure if you do change, that you keep the same thread pitch! have seen more than one oil filter come off during a race because people switched brands, and the threads are different. it will thread on, but shake itself loose.
I change my gear lube every off season, so 25-30 races. I'm sure it's good longer than that, but I like to start the season fresh. I use Redline lightweight shockproof gear lube
Fuel filter. I recommend and only use my 10 micron fuel filter. Normal fuel filters are 40 micron usually in this size. Biggest concern is with ethanol in the fuel around here, it degrades the fuel cell foam more quickly. Get a little foam in your carbs, and then you need to go through them.
You messed up the synchronization on your carbs. the rear of the 3 screws syncs the back 2 carbs, the front one syncs the front 2, and the middle one syncs the fronts to the rears. Find someone at your track with a synchronizer, they can have you ready to go in 20 minutes. I've sync'd many a carb at the track for customers on race day