As you can probably guess, I'm all for Dodos, but I am not for replacing the Skimmer. Adding Dodos at the airport would make more sense. The fpslimit thing is an issue, but I'm not sure it can be fixed- and an even bigger issue is being able to get a passenger inside. The Skimmers were carefully placed so it would be relatively easy to get in, but elsewhere, it's an issue (I think this could possibly be fixed with a script, however).
Water is weird and pulls/slows you down way too much in GTA, which has always bugged me- I've found that minimizing contact allows you to mostly avoid the slowing effect (you can ram a swimming person with the wing of a Rustler by only using the tip of a wing). If you want another tip besides /fpslimit 20, try tilting the Skimmer to the side when you take off, so it's only on one pontoon and you avoid some of the weirdness of water. In real life, float plane pilots have to do weird shit to get the plane out of the water too, like the elevator pumping in
this video (the pilot also doubles back on their wake to get the floats to hop out of the water more easily).