Experimentation is great ........... but ....... this is in the beginners forum and its a trainer.
I also think option 4 is the best way to go.
There will be very little benefit of having two servos, unless the extra weight and the extra current draw are considered benefits.
As far as it being easier to trim (what I think you really mean is to set the end points) you will be better off if you learn to do it mechanically instead of doing it with the TX.
Getting that accomplished is not hard to do either and there are plenty of us here to help with that if you need it.