Fortifying, diamond tip, heavy hammer, the one that increases stone damage for my pickaxe.
Fortyfying and diamond tip makes you use less repair packs. Big deal, not something anyone would call crucial. The mod that increases stone damage saves a little time, not crucial
Yes, everything you perk in or add to your weapon makes you slightly better, but that doesn't mean it is crucial. Look up the word if you are unsure.
In fact, since stone doesn't hit back and no single mod makes you get lets say 30 or 50% more stuff in the same time, nothing of that is what you would call a game changer
How about I do armor?
Mufflers, improved fittings, armor increase and storage.
Mufflers are crucial to agility players, merely nice to have for everyone else. Storage is absolutely in the nice-to-have category, with a vehicle you can always guarantee to not overfill or you simply use a perk point for packmule instead. Armor increase is one that you usually never want to go without, so it is important. But not crucial, otherwise nobody would run around in anything but heavy armor. Some people choose to not get hit instead of relying on the best armor.
Or guns?
Cripple em, red dot, silencer and extend mags
Considering that you said silencer I guess you mean pistol/SMG. I would prefer 2x scope to the red dot but maybe they improved red dot from A17.
Cripple'em has a 20% chance to cripple a zed. Since it is only a chance you can never depend on it saving your life in a critical situation. It is surely nice to have, but that it only works sometimes shows perfectly that it can't be a critical mod you can't live without.
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EDIT: Ah, okay, saw your last post. With "important" I can agree. The thing is, assuming you will play the game about 3-5 weeks without finding a Quality6 pistol, will you only run around with Q3 pistols for all that time even if you could craft a Q4 pistol at day 8 and a Q5 pistol quite easily at day 14 ?