To put a finer point on this (and since we also ended up discussing carrier movement in addition to placing one), it doesn’t even have to be “likely” for there to be a landing place, just a non-zero chance.
For instance: If the only way a carrier can make it to pick up planes at the end of their range is for you to win a battle with 1 sub against 146 battleships and then the carrier NCMs through the cleared seazone for the planes to land, then that’s a valid landing place as long as you attack with that sub…
I don’t think this is correct, since you are supposed to assume that all of your units will miss and all the defenders will hit. That is, you have to assume that you are going to lose every single battle so you can’t over-stack in this way in anticipation of victory (I know this is explicit in the rules, but don’t have one handy to quote chapter & verse).
You’ve actually got it backwards. You’re permitted to task fighters assuming you’ll WIN every battle.