I can't speak to the driveline point - if your bike has the original crankset and original BB then its probably correct.
My method for front derailleurs is something like:
- Set the height of the mech so that at maximum reach it clears the big chainring by 1~2 millimetres.
- Set the rotation of the mech so the cage is parallel to the chainrings.
- Then I set the high and low stops by eye.
- Finally I set the shifter cable and with indexed shifting I focus on the big chainring.
After this it gets less "method" and more "iterative" Personally I ride in the big ring mostly, so I set that up to have no chain rub at in any rear gear choice and accept the grannie will rattle a bit. But if I'm in the grannie then I'm probably climbing something steep, and most of the bad noises will be coming from the rider :)
Note that derailleur cages are relatively easily bent by impact. Additionally, some derailleurs need to be rotated so their tail end is subtly in-board and thus the cage is not parallel to the chainring.
Front mechs can be very faffy. One thing that makes it easier is when the whole area is clean, so degrease and clean the chainrings, shifter, cassette, rear derailleur, and chain. Try to elevate the bike too - working with the rear wheel on the ground is no fun.
Your limit screws are not at their own limits - they can be backed out till the thread inside is flush with the inside of the metal, and can be screwed in till the head bottoms out. If they're stiff, consider adding some oil like CRC or WD40 to get them moving, but also consider they need to be stiff to not back out under pressure. Just ensure your screwdriver tip is a good fit, and that you don't camm out the screw head.