I don't think this is much of an issue at all. It seems that the MM takes special care when it comes to CV balance between teams, and BBs second. CA/DD, not so much. 2-3 tiers does not mean a huge difference in survivability or damage potential, at least not to an extent where it's impossible to contribute sensibly. And the experience gained is improved significantly even if the contribution does not feel to make as much of an impact as in same tier games. There is so much to do in higher tier games: support, or even draw fire at the right moment, spot, cap, etc. If you know the other instalments of the WG games it's a marked upside of WoWs, in the other games 2-3 tiers higher means 100-150% more survivability of the opponents while they output twice the damage.
I rather enjoy the specific national differences in squad size and the leaning towards DB or TB, respectively. I also concur that the options on loadout are too limited. I tried IJN fighter squads for a couple of games and then just dismissed it and changed my tactics. And since spotting itself is not a mechanic with its own rewards (and might not contribute enough to a game to secure a win), I just wonder if US CVs are too limited in role since the patch (except perhaps the higher tier ones). What I would like to see is that flight control modules upgrade the maximum number of squads of one type (+1 fighter, or +1 dive bomber, etc, compared to the default loadout), and then have the player select the specific loadout via the ammunition tab. Maybe that's what WG is planning to do, anyway. So perhaps something like this in in the pipeline, I'd certainly hope so.