Sounds like his Aux fans aren't running. Even if the viscous fan were totally dead, the Aux fans should have moved enough air to keep the pressures down.

Proper charging is ALWAYS done at full load with the fan on high (all windows down, max cold, max fan, in the sun if possible). MB has a really stupid way they perform "tests" on their system that differ greatly from the way the rest of the world works. If he charged properly, he should be 30-32˚ below whatever the ambient temperature is with the fan on high at the center vent at idle. If it's 85 outside, that would be 53-55 at the center vent. Once moving and the system has a chance to pull down the cabin, the temp will drop and the fan will ramp down.

The black paint is there to help the condenser radiate heat. The same thing applies to heatsinks for electronics. Black anodized parts have a higher heat rejection capacity than their bare aluminum counterparts, even if the exact same casting.

Sounds like your friend is an "armchair expert" and well versed in the garbage read about on the Internet from other "armchair experts".

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]