Dostayer

AA : Teratorn is slow-firing, but a hard-hitter. Knightframes are mediocre at best, tho
Disguise units : Use Stun-Grids/Clairvoyants

I find that with high speed airplanes (especially the annoying black widow or the harbinger) you really better off with something that hits instantly or has a fast projectile rather than a strong one, Flak cannons with their variations are absolutely the best when it come to this (especially the Sentinels, probably the AA unit I fear the most) along with Skyray and Aeroblaze, the Gatling cannon is less effective due to warm up time and the low damage output until then, the Patriots are fine but the shrike is useless against any aircraft which is not slow moving (Kirov, Helicopters, Yuri's hovering units and maybe the barracuda, and if the are with their own AA it's unfortunate).

I think it's hard-coded in the Engine, some things are just not modable without knowing the source code/obtaining the original development tools/design.
Some things, the engine can't do at all (it's especially evident in how aircrafts were implemented before RA2).
It's not only in this game, In Sonic Generations you had a hard coded limitation on the number of levels that can be in the game, and you can't change bosses beyond color palette.

I personally think that water is pretty much the same as land, just without elevation (besides the shore, that serves as a cliffside). So if land based units are allowed to have such diversity, then naval units should have something similar too.

Also, I wonder if the driller logic could be made to work with naval units. There could be a Deep-Sea Submarine, or something similar.

I think the engine itself doesn't have such option, C&C engines were never meant to have such complexities, for example: different attitude levels for aircrafts, that's one of the reasons why you have so many different aircrafts which seems to sit on the same roles, so goes for terrain and tanks (especially urban terrain, some tanks, like the Merkava 4, are specially designed for this, put a T-80 there and it will most likely blow up. Or the K2 from Korea which is designed to deal with the hilly terrain of the peninsula etc) CNC never went for such resolutions because it has a much smaller scope...

Funny enough, the CANC game which came the closest to properly portray Aircrafts was Generals, from there it went down hill...

Yeah, but it's an alternate universe. It could be different.

There's a limit of how much can be changed in an alternative universe which its history is more or less similar up to 1924, one of such things is the population of Australia.

 

As far as additional naval units go -- I think it might be hard to add too many new ones without adding unnecessary bloat -- but I keep thinking an Allied Chrono-ship would be useful, to teleport into small landlocked water areas for more harassment options.  Maybe for Euro Alliance.

 

I thought abot it more as a replacement rather than addition, factions already has ships for all of the roles their navy needs (in the scope of the C&C franchise ofc), especially considering the fact that, with the exception of Russia, no subfaction has a unique Naval Unit of its own...

The mission gets darker by the minute, that's the point.

Well that explains a lot, I've reached to a situation I almost see nothing, which made to whole endavour almost impossible operate.
What is the time limit before it becomes too dark? it seems like a little after the Sabetour part it darkens very fast...