The cambelt change is an essential...and at of before 60k miles.
If not done then I'd be careful about giving it a good thrashing
even on a test drive. But....that's up to you.
Turbo should not be a problem.....a possible cracked manifold
might be though.
From cold...open bonnet, and remove the
exhaust heat sheild so that you can run your hands/fingers around
exhaust manifold to see if they come out with a black sooty deposit.
Other than that, all you can do is get someone else to start the
engine..again FROM COLD. Then listen carefully for any exhaust
leaks...don't rev it.
If it does have a leak/is cracked, then PM me and I'll point you
to a company that makes a stronger standardish 'steam pipe'
replacement manifold that costs less than a genuine Smart one.
What else....the rear shocks. They're known to leak.
Other than that...just the usual checks you would make.
Hope ya have found a good one though...and if so...enjoy