I personally dont take teeth into account when calculating discs - in the end the calculators not going to be 100% accurate and theres a chance of getting an unusually good or bad hit, and therefore it makes sense to take account of the teeth by rounding up rather than any calculation - and at the end of the day, a sufficiently powerful spinning object is the same give or take a few kilojoules, at least once you get over 50 :P

My main reccommendation if you want to make the disc more powerful is to make it thicker, and thus heavier, or make it out of a different material for more weight...considering the drive and armour though, going above 20kgs with the disc weight is pushing it. (let me know if you have problems calculating stuff for the disc and Ill throw something together)

Which brings me back to the armour...3.25mm Hardox all over the machine is still going to cause problems, you can keep the Hardox on the front maybe but youd have to have some Ti on the sides at least and maybe a polycarb base, without doing weight calculations I cant reccommend anything specifically but as it stands its probably overweight.

And I have to agree with Marti about the length/length confusion, it is an error and you shouldnt be yelling at him for pointing it out :P