You do realize you are kind of implying it is your right to be as well-equipped as the people who invest heavily (as you must) into crafting. This is a bit like me complaining I have a hard time hacking everything to death with my towering intellect of 3. Crafting was largely made redundant when there were so many exploits in the game, this restores some balance and usefulness.With your suggestion you are forcing everyone to spec into the technical skill tree to fix an issue with loot itemisation.
Much easier to just change it so that each loot tier will roll with a fixed number of mod slots, see my post above yours. That single change would address all your points and be much easier to implement. CPDR can "fix" crafting separately.
Besides, no one is forced to adopt any particular build. There will be very good options, just not at your save-scumming fingertips. This will mostly negatively impact the customization options for those who value substance over style. But it will negatively impact everyone and lessen realistic customization options and this is bad.
That said, the huge variation in mod slots is another mark of poor design. Legendary clothing with 0 slots is legendary in name only. A rare with a single slot would be MUCH better. Your idea is a sound one, though to completely eliminate randomness also eliminates the excitement factor of finding the perfect item. I would suggest rather to limit it from 0-4 for legendary inner torso to for instance 2-4 or 3-4. This way you keep the luck of the draw excitement, but don't completely frustrate players with bad luck/little patience.