I see no reason why the WW1 arena(s) could not eventually have some early tanks, bombers, observation ballons, Zeppelins, towns and fields to capture with wars to be won. Frankly it wouldn't bother me to see the game evolve like that over the next dozen years or so, but I am not hard up for it at the moment. I am having a blast playing the WW1 game right now as is.
Do the collisions bother me? No, not really a problem for me. Do the HOs bother me? No...they are far less effective and far easier to deal with in the absence of heavy cannon and rapid closing speeds. About the only difficult thing that has happened that I can see so far is some side imbalancing, but it seems to be very fluid at the moment.
Lastly, just let the current set-up settle in for a few months. The late war peeps wont be around once the novelty wears off and the regulars will start to get their dope lined up making for some intense A2A combat (some already have, myself excluded).