So in the original Pillars i remember that all specializations work on soulbound weapons. so for instance you could use two weapon proficiency on a twohanded weapon to add 20% attack speed.

I wanted to do the same thing with Lord Darryn's Voulge on my ravager. Do soulbound weapons still interact with proficiency this way? Im trying to make a resolve crit ravager build with shattered pillar.

That's not correct. Soulbound weapons did use any Proficiency Accuracy bonuses in PoE1 (regardless of weapon type). However they did NOT use fighting style bonuses for category other then their own (2handed using 2 weapon style 20% speed bonus like in your example). They got the bonus relevant for their category instead (+15% damage).

Now in PoE2 there are no proficiency accuracy bonuses, so....

And no, they can't use "any" weapon type modals.