Yes, yes
Probably
Yes
Why do you want to do it? A lot of work.
5th is soooo long I wouldn't bother. Custom mounts will have to be made, probably custom drive shafts, then you have to work out if they will fit the hubs etc.
If I was spending any kind of large money on transmission it would be for the 5spd SQS Gearset.
It won't fit between the chassis legs