I've got a 190 as well and my trunk unlocks with my doors. Yours should probably due the same (vaccuum). As for your water pump, it should not be noisy.......Replace the pump ASAP and flush the entire cooling system, evaluate the condition of the fluid. If it is rusty you'd be wise to replace your hoses and possibly your entire radiator.
Smoking exhaust is another red flag. You could be in for some expensive repairs. What colour of smoke are you seeing? If its blue its going to cost $$$ and if its whiteish and thick and cloudy its going to cost $$$$.....
Look for an independent MB shop in your area, make or read some posts in the forum dedicated to shops.
Best of luck with your 190E!!!
190E 2.6 - 244 000 km