This is actually something we have moved away from in a major way since retracting the E to 6 teams. Last season we had 0 inactive veteran players, this year we have two per team because the GMs voted 4-2 that they wanted them this year. I personally think we can be completely healthy with 0.
The actual issue with any "delete the E talk" stems from the cap question you mention. We've been over this many times since even before the inauguration of the VHLE, but there basically has to be one of two outcomes here.
Either: a)we keep cap at 400 as you suggest, but we don't think there's any appetite for brand new players to play against a good chunk of players at 300+ TPE, or b) we move the cap to 200 or 250 and the VHL supports the excess, but right now the excess is big enough to require either expansion or raising the cap, which comes with it's own issues as well.
The long and short of it is as long as there is some form of recruitment effort, deleting the E would most likely require either expansion or forcing new players to play against too strong of opposition early on, neither of which have been at all appealing based on multiple discussions.