2009 MCS R56 - about 86k on it.

I have been having a ton of issues and lots of different codes, so I started replacing stuff. I have had misfire codes (P0303 and P0304), idle air control system RPM higher than expected (P0507), multiple misfires detected (P0300), boost leak (P1497), and a few I don't remember.

So far: I had a coolant leak, so I replaced the thermostat, water pipe, and pump.
Then I started having the limp mode and CEL problems.

The guys at the dealership ran codes, inspected my timing chain, and did a smoke test for me and found my catch can was leaking air, so I deleted the catch can and reconnected the PCV directly to the intake track. Still had a boost leak code.

Then I did spark plugs and coils. Car felt great but goes back into limp and reactivates the CEL.

I was getting weird, really rough idles, with no turbo spool or pressure release/recirculation (I have the spacer installed so it can blow-off rather than recirculate). If I had been driving for a few minutes and the engine was warm, the RPMs would climb and hold (usually at exactly 1,500 or 2,000 RPM) until I gave it a light rev, then it would fall, sometimes this would keep it at idle, sometimes it would just keep revving.
They did another smoke test and we discovered my valve cover was also leaking air/smoke from near the PCV itself.

So I replaced my valve cover.

I still get the limp mode and CEL back after clearing the codes and driving it. I start getting the symptoms like I described before, the revving issue when stopped, the lack of turbo-spooling and no feeling of boost, and the boost leak code.

So I replaced the HPFP and the flexible hose for it. Same code and CEL, no limp mode for over 3 days of driving about 10-15 miles.

I also did a fog light replacement and replaced the exhaust seal/gasket (mine was in pieces) because I had the bumper off and had a bit more room. I inspected my turbo on the block and the shaft of the turbine has light play and so does the actual waste gate. The guys at the dealership showed me a bad turbo with more play but they explained the symptoms and said while my turbo may be old and worn, it's not bad enough to warrant replacing, they insist I have to find this boost leak to see if eliminating that will give me a diagnosable problem, or a fix to the current problem.

I need some serious help. I have removed and inspected my recirc. valve but found no cracks or tears.
I did some starting fluid boost-leak checks on the charge pipe near its sensor and where it comes from the intercooler, as well as the intake manifold. No signs of a leak.
My valves look pretty bad, so I will need a walnut blast in the next 2,000 miles.
I will be replacing my crank shaft seal and belt, as well as possibly doing the timing chain (no cracks or breaks in my guides luckily, just a degree or two out of sync), all in the next week or 2.

I'm sure you may have more diagnostic questions for me, so I won't expand more. I have included as much relevant info as I can. I just want to get it running normal again so I can continue putting upgrades on it. Any help is much appreciated.
All your help is appreciated.