The amount of posts related to chip tuning (i asume that you mean stage 1 chip) is insane. Use SEARCH button
And I know at least Unitronic tells you what is required for each stage tune. I'm sure the others do too.
Stage 1 is commonly a tune and upgraded diverter valve to handle the boost. The DV is optional. Other upgrades that might be considered "stage 1" might be a turbo inlet hose.
The problem with "stage" whatever is that there isnt a standardized unit of measurement. "Stage 3" for APR tuning is probably different for "stage 3" Unitronic and so on..
As far as saving weight it all depends how comfortable you want to me. In my opinion? Keep everything and just keep the car clean. No huge sub in the black, no trash, no 30ibs of clothes that need to washed, ect..
“A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”