Does anyone think this mod will be worth playing? Is it too far out? Too far fetched? Or do some of my new toys look appealing? Overall what do others think of a no naval treaties world where there is plenty of license to fabricate new ship types.
Seeing as I'm intermittently working on something similar myself (but with deeper changes than just the Treaties), I'm going to say it's definitely interesting, whether it is worth playing is a question for the individual person and their own preferences, some people are focussed on historicity, some are more open to what-iffery.
A different, Naval Treaty-less, world will necessarily lead to different design choices, and on that basis the stuff you're proposing doesn't seem too outre. I'm going down a slightly different path, keeping existing designs largely as is, but focussing on the Cherry Trees and other designs that never saw the light of day. One thing to bear in mind is that those naval changes won't happen in isolation, they'll be matched by similar changes in ground and air deployments. The opportunity to see FM-1 Airacudas taking on Japanese strikes over Clark Field, or Airabonitas flying off the Yorktown, or Reapers in the air over Singapore, has a definite attraction. I can't say if I'll ever play the mod if you release it, but I'll certain probe the living daylights out of its database for ideas I can use for my own mod, ditto for ship or aircraft illos.
Ultimately it doesn't matter what anyone else feels, it's a hobby, and the only question that needs answering is whether working on these changes entertains you?