ok, got one in mind...
yes
yes
not the quietest of rides, but I've always found it comfortable for long journeys
well it's not gonna be a hot-hatch in that dept, but you can throw it round corners in the dry confidently.
height-wise you'd be fine - not sure about width but should be OK at 15 st, unless it's all accumulated around your arse whereupon it might slop over the sides of the seat into the door tray or interfere with the window controls ;-)
seen baby seats attached to them - should be fine.. has split-fold rear seats too
uh-huh
nice.. this car would be a good appetiser for something of that performance level
what car am I referring to? A Rover 600 Ti.. there's a nice one here and currently for half your budget, yet probably just as much fun as other cars you could get for 3 grand: