[rnln]

about rebar, I saw them worked on another house by using a long rebar to knock down from top to the bottom. Of course, it's not as perfect as building rebar since the begining because this rebar won't go through the foundation. Instead, it's stay on top of the foundation. Then he did pour cement through the whole rebar long. The rebar extend up through the whole new blocks. Although, it doesn't go through the foundation, it's still better than without it, especially with full cement inside.
First reason was privacy, yes. There are tall guys can look through the 6' wall while walking. There are people just stand there and look into my property. Also, rocks fly from cars hit window. I like a tall wall better than wood top because I can stucco it and paint it from top to bottom. But if it's not allowed, then wood top (or anything light) will have to be the case.
Thanks guys.