Yet another "watk vs stat" question...

So since I'm a Pure Str DW, My 2h sword will be much stronger than my %str shield with 10 str and a 1h 95 att sword?

Um... no. It all depends on your weapon speed and how much of a stat difference the two sets have.

If you have a 140 attack Devil's Sunrise and pit it against a 100 attack Sparta and a shield with some %STR, then the two-handed sword will be stronger, because of the huge weapon attack bonus. Now, if you were to use a 120 attack Red Katana against a 130 attack Devil's Sunrise and you had a % STR shield to go with it, the Red Katana would dominate because of the weapon attack speed change alone.

As far as different weapons goes, there's more to think about than just miniscule attack or primary stat differences. Of course, this doesn't hold true for all classes, like the ones who have the exact same weapon speeds throughout the game.