breakurnees -
One thing for sure springer fork is probably not well suited for speed. You should really just try swapping the fork to a BMX fork something with a 30mm offset will give you a silly stable ride, like hands behind your back in the straights. Although you will have a bit of wheel "flop" when you steer with the fork to much. I think you will be happy with the results. Flipped frames are all about body language, which scares a lot of folks. You could always move towards a 0 offset fork (flatland bmx fork) for tighter steering. S.I.N Brothers have went through multiple forks from wrecking our consensus is to use the beefiest forks you can get a hold of! I have ridden flipped, not flipped, and of course our hybrids that combine a bit of both. They all just take getting used to, and sometimes run better on different types of roads.
Kneelers are great, but you can not solely depend on them, having sturdy rear pegs is super important. Being able to shift your weight between handlebars, knees, and pegs is absolutely key to getting the most out of any road. We have found seats to be near pointless except for causing serious damage to anything between your legs guy or gal.
Keep riding!