While I'm a little lighter than DAD, 170 vs 200, I used the same 5/8" spacer addition as DAD. I don't recall the exact oil level, it was about an inch more air space than Dad with 15 weight oil. Much of my riding is two up and I have full 3pc. hard GIVI bags. I also install tapered roller bearings this year. The original ball was slightly detented and dry so the new tapered rollers feel sweet. If the ball type had been in better shape I'd say 6 of 1....

 

Only if they are worn.

Ball are actually much smoother. Thats why a lot of manufacturers still use them, but they dont last long and are not very strong.

As a rule I replace all bearings every few years as its cheap insurance.

 

Tapered bearings? Yes, but as mentioned, only if they're flat spotted. Mine made 43,000 before needing replaced. I used tapered replacements which are near bulletproof BUT, need to be cleaned and lubed every 25,000 or so. They start to get spots that aren't really free running from the grease drying or being displaced. Check the same, by unweighting the front and checking that it's free running, no drag. It's subtle so it's easy to miss but the bike feels much better with a freely operating steering head. With the tapered it's usually just a cleaning and fresh grease required instead of replacement.

 

The steering head bearings are ball type from most manufacturer because they make the most sense. Tapered roller are best suited for full 360 rotation and high speed. They can handle great loads, but generally aren't the first choice for a thrust load. As DAD said, keeping them properly maintained makes all the difference.
Ball type bearings are perfect for this job. They can take the pounding the front end gets from the road and cost way less to boot. So keep 'em clean and greased and leave the jumps and stunts to lighter bikes!