imo, I would perform your upgrades in steps rather than all at one time.
I would first start with some checks and balances: checking all your lines and condition of your oil separator and related lines top and bottom, air filter box for any oil contamination including the MAF (use CRC MAF cleaner) and the throttle body intake line, oil and filter change and s/c oil change, rad hose and replace those first.
Then do a good internal cleaning with seafoam top end cleaner and berryman.
Relocating the MAF closer to the intake (up top vs. OEM location beside the radiator) does improve the dead spot around 2000-2400rpm. Easy swap. Search on Benzworld for the oem part bag to do this swap and/or use a 2.75' down to 2.5" silicon 90 elbow reducer (what I did) to connect the intake from the I/C line to the MAF for a smoother air flow transition from the I/C.
For #1, I'd stick with Bosch Original Equipment 0280217114 Mass Air Flow Sensor (MAF).
For #2, this works fine, or you can go nuts and use an adjustable one. - https://www.ebay.com/itm/New-VW-Audi...c/111963132346
I'd hold off on the intercooler for now to see how each stage upgrade works out, unless you really have a desire to pull off your front bumper...
#4 dont know who this seller is as the listing goes nowhere. imo, I would not swap out this one. The OEM clutched pulley is the best development MB came out with for the Kompressor. You remove this and your mileage will degrade, more stress on your 2.3L with the S/C running full-time (you're asking for potential headaches down the road)
#5 Speer main crank pulley kit - best back for your buck. sells on fleabay too. (this would be the first step for power upgrade and no REMAP required) You can REMAP later if you want but then you'll need to upgrade a few more things with this REMAP.
Note: adding upgrade pulleys has it's caveats too: read up on it at the other forums.