No, it is not. It would be either most sweet, or sweetest.
No, "most friendly" is not grammatically correct. The correct form would be "friendliest" when comparing three or more things.
Yes, the sentence "He is their most targeted receiver" is grammatically correct. It means that he is the receiver who gets the most passes thrown to him by his team.
No. It is my favorite place is the correct spelling. Most is implied in favorite.
"Not like that" can be grammatically correct, depending on the context.
Yes! That is grammatically correct!
Yes, 'for free', is grammatically correct.
This is not grammatically correct. The correct form is 'you do not know', or the abbreviated 'you don't know'.
"That was wrong" is a grammatically correct sentence.
'What a drunkard you are' is a grammatically correct English sentence.
Yes, Almighty God is grammatically correct.
Yes, it is grammatically correct.
Sure. It would also be grammatically correct to write He spoggled his nubbix on the goober. Grammatically correct and meaningful are not the same.