-Your current I-94 is the latest one using AP to enter U.S. on July 30.
2) What is my current status? H1b or DOS?
-Absolutely AOS.
3) Am I legal to work using my current H1b
-No more H1 unless you file another H1 petition. Because you did not worked for Univ. B yet when you left U.S. with AP, you can not work for Univ. B using H1. In other words, only you were working with Univ. B with h1 status and you used AP to come back, you can continue your work for Univ. B without using EAD.
or do I have to use EAD?
-Yes.