I think you are looking in the right direction.
I car top my TI and load from the rear so I can tow my caravan as below.
I made a frame which sits on top of the roof racks which has a roller at the back.
This allowed me to electric winch the lot into the roof of the garage for storage.
I also was happier with a pole at the front as the car, Hyudai i30, is not long.
This supports and also holds down the TI at the front so it is secure at speed.
I found I needed a frame at the back which attaches via the rudder pin.
This prevents the TI from moving back when I lift the nose with no-one to help.
I am 65 and can still lift the front onto the top of the car but it wouldn't want to be heavier.
Cheers from Brian in South Australia