[ProPain]

I don't think you should make yourself unappealing to Burgundy. Burgundy and France will end up in war, one will grow huge from it and that will seriously hamper you expansion options to the south, possibly even threathen your existence. Also Burgundy owns the Antwerpen CoT which is a huge boost to their income. The longer they have it, the stronger they become. You want that CoT.

Imho your best option is to fight Burgundy asap and make sure you get Antwerpen and at least one more Burgundian province from the 'belgian' chunk in the peace deal. To win this war in the early years 15K-20k troops should be enough. Put them all in 1 stack and fight defensively (only in your home provinces, not on B's turf) at first so B's armies suffer from attrition. Pick of armies that you can annihilate decisively without too much losses (practically: only fight armies that you outnumber at least 4 to 5 times). Avoid other fights, run if needed.

At some point you'll notice that B's war capacity will drop to the red (<25% ???) which means they don't have the manpower to reinforce their troops anymore. From that point on you can take on slightly more even fights. Once B won't be able to reinforce at all, you can simply clean up and occupy provinces you want to have out of the peace deal.

Be wary of occupying the southern B provinces. You'll be suffering from attrition yourself and reinforcing is slow. You'll easily get kited and run the risk of losing armies at little cost to B. Only occupy the northern part of B when you need a higher war score to force the peace deal you want.