i did not read every word written on the problem.

did you check fuel pressure? can you check it while driving? sounds like the fuel pump is tired or wrong. every problem i've seen like you describe sounds like low fuel pressure and volume. even new pumps that are sold for these cars but are not bosch do this. so, no airtex, carter, walbro-nothing but bosch if you have to replace it. and yes, you could very well have a tired bosch pump. this ASSUMES the feed pump is working correctly. the main pump has no guts if it has to pull from the tank and push to the engine. verify tank pump volume and fuel pressure at the engine. good luck, chuck.