Morning Graeme. Yep, home for a few days at least
American? Grumman or maybe Gulfstream
Not American...a European design.
No....side-by-side seating
Jet exhaust at the extreme end of the tail?
No, the engine itself is immediately behind the intake....the exhaust appears to be directed either side of the vertical tail surface (I've reached that conclusion from the picture and 3-view).
Closing down in a few mins mate, but hopefully you've now got something to think about on your Sunday morning!