yep

yep

Yep

yep

yes

yes

yap

yap

yep

yep

yeppe

Yop.

yep

Yep

yar

Yes

no

Absolutely not

All scaling attributes have a range. So B is like between 74.9% to 100% and A scaling is 100%-149% and S scaling is 150+% So not all B scalings are the same. (That's why you get more scaling from upgrading a weapon from like B- > B (If it's blue while still just being B - > B it means that its scaling is improved but not changed ranking)

The letters are just an indication and often depict a broader range of gains. The dex scaling is undoubtedly better than the regular path, but expect to see the difference on higher dex.

You need keen to have a B scaling dex on that weapon before reaching +25

Keen will be a downgrade until later upgrades and unless you are focussing on dex without putting points into strength. Cold feels really good.