My car: 2010 A4 Quattro prem plus 6MT 60k miles

Hi, I have been getting various CELs lately. Since the car drives fine, I just erase them . The CEL codes are getting more threatening though, so I hope you can help me pinpoint the root cause issue.

There are posts on this forum discussing each of the various CEL codes I am getting. They point to multiple possible issues though. I hope based on my description below, we can narrow the possible causes.

So, in Jan and Feb I received code P2015 4-5 times: Intake Manifold Runner Position Sensor/Switch Circuit Range/Performance Bank 1.

Then there were no Cels for a few months. I drive ~1k miles/month btw.

Then in July I started getting this 4 codes combo:
P2015: Intake Manifold Runner Position Sensor/Switch Circuit Range/Performance Bank
P2187 System Too Lean at Idle (Bank 1) DTC
P0507 - Idle Air Control System RPM Higher Than Expected
P2279 Intake Air System Leak

I would get the combo above approximately once per week till two days ago, when the codes became more threatening:
P2279 Intake Air System Leak
P0300 Random Misfire
P0301 Code - Cylinder #1 Misfire
P0302 Code - Cylinder #2 Misfire
P0303 Code - Cylinder #3 Misfire
P0304 Code - Cylinder #4 Misfire

The car drives fine as always. I reset the codes and there has been no Cel for 2 days now

Pls help out. What do you think is the root cause?

Thx,
Michael
Maf sensor?
Pcv?
Coilpack?
Hpfp?
Other?