Frontosa require time and patience, both of which you seem to be lacking. Your attitude is off-putting and I wouldn't be surprised if this is why you haven't received more valuable input on your thread.
You have some nice Burundi but keep an eye on the one in the second pic on the far left, its bars should straighten out as it grows but are not as clean as a breeder would look for. Driftwood is also not ideal in an African tank and especially not with Tangs.
In regards to the questions you have asked, keep your PH around 8-8.4, coral sand is a good substrate and buffer. Feed NLS Thera +A, brine shrimp and then krill once they've grown, fresh Australian prawns chopped up and the occasional dose of peas and algae wafers to clean them out and prevent bloat.