There are already trends to overcomplicate things.
SIMPLE is the word you have to keep in mind. So there will be no travel delays, field camps, there will be no effect on unit size or composition. Nothing of that kind matters when you're onboard a ship.
Yes, islands will become strong, but at the same time they will have trouble attacking the continental areas.
I already answered the landing question: If you want to land somewhere, you try it. If there are too many defending troops, the landing operation will be aborted, at the cost of some hours, and you will be told. That is what you will have in "scouting".
