Clear out the turbo and associated piping the best you can, and drive it much longer than over the weekend.
It is too early to decide the turbo is a problem.
Do a rad pressure test and see how long it takes for the pressure to drop. I think you can buy them for home use and they are not too expensive.
I bought a Gen 2 SHO that did not leak a drop of coolant on the day I bought it and drove it 300 miles home. When I flushed the coolant, it leaked a cup a minute. It had been doctored with "stop-leak" in an amount that defied description.
I cleaned up the system, changed the pump and never had a moments trouble with the heater core or any other cooling system part.
Try some stop leak (and try not to listen to everyone who will tell you it is the worst thing you can do). If you use the one with solids, boil the contents on your stove before you install it.
Keep driving the vehicle to see if some of your symptoms clear up.
Your dealership doesnot sound like a classy place to me.
Your dealership has your car at a point where it would make sense to drop the whole subframe and engine and make all your corrections at once, yet they are not offering you that. They seem to prefer the drip -drip - drip approach.
Keep driving it till you find a decent shop or dealership.