Hi,
What we believe at SonarSource, and what we’ve designed the interface to enable, is that you can gradually improve overall quality by focusing on the quality - and in this case the coverage - of New Code. We call it the Clean as You Code methodology, and we’ve created a web page and I’ve written a blog post to explain it.
Basically, just ignore overall coverage and enforce that all New Code has 80% coverage. Gradually - and this was our own experience internally - overall coverage will naturally increase.
HTH,
Ann
P.S. It’s best to keep it to one question per thread AND you’ve already asked your other questions elsewhere.