I too am happy with my ms3.
Its a 2013 with the jbr rear sway bar, rear motor mount, and koni yellows with swift springs. All I can say is handling is superb.
I know mazda has a accelerated idle on startup to 'warm up the cats', and I do see some white smoke out the exhaust while this is happening (may be fuel) but no loss of coolant. What symptoms, if any, did the smoking turbo exhibit?
As far as the egr system, any build up on the intake valves?
Its obvious you take care of your car and with 150,000 miles it shows. congrats!