06 Sebring oil leak around map sensor, crankshaft sensor, damaged camshaft what is it?!

I took my 06 Sebring 2.7L engine to
the mechanic today but I need a
second opinion. Here's what's been
wrong: have to fill coolant before you
drive, oil pan leak, had trouble
starting (but now does with new
camshaft sensor), there has been a
lot of smoke coming out of exhaust
when you first crank it, acts like its
going to stall out at stops/lights,
when I replaced crankshaft position
sensor and mapping sensor there
was oil residue from the part that
was attached to engine. Engine light
has been on but went to diagnose at
AutoZone and no codes came up but
it never went off. Oil light is now on
too. Experienced some overheating
today but when filled with lots of
water it leveled for a short drive...
While I trust the mechanic he also
charged me $90 to install the
camshaft sensor (a $20 part if that.
Not in difficult location) and 2 liters
of oil... Is this really a "need a new
engine" problem or could I save the
sebring? I don't plan to have it much
longer as it has 215,000 but I do
need it for a couple weeks to get
money on a down payment. As of
right now I'm too worried to drive it.