Newbie questions, cat food

I am complete newbie and just discovered this group. Therefore, I'd
like to ask a few questions. I realize that even among the experienced
there may be no consensus. When that is the case, I'd opt for
diversity, so no error is compounded too much.

1. Canned v. dry food. I think people seem to prefer canned, but some
make a dental case for dry. It is also more economical. So maybe feed
mostly canned (75%) and but a little dry too?

2. Of all brands (both cans and dry), which ones you feel offer the
best dollar value for nutrition? I fthey are only available through
some specialized channels, please include that as well.

3. Mix dry and wet? That is, should dry food be physically mixed with
the canned food or served separately?

4. Add another spoonful of water to cans? So much praise for canned
food appears to be for its moisture content. If that's so good, should
I just add a spoonful of water to a can?

5. Of the inexpensive brands, which ones are best nutritionally (both
canned and dry)?

6. Finally, is it ever desirable to give any human food to cats?
Yogurt, tuna, chicken pieces, veggies, cheese, anything?

Thanks.