That will do just fine. I have one in a 60 breeder and it barely ever crosses half the tank at feeding time. I find them to be more active vertically than horizontally.
No you can’t as these need 4’ minimum IMHO. It’s not their size but their swimming space. If you ever see one in a 4’ tank and displaying to its full, they really use it all. You cant forget they flash, if you forget that then you aren’t considering the need for full swim room.