From my experience, the most you can sell is 60 days. You don't have to take terminal leave, but if you dont sell it the you lose it. But if you decide to sell it, then you will lose BAH, BAS, and special allowance if that applies to you.
It means VA either was about to rate you claim and something on the claim need to be clarify. The VA would open a ticket and request from QTC or examiner for clarification. This often dont affect you directly. This only takes a litlle more time on the process.
Did you ever talk to the DOC on the phone about the DBQ? The PEBLO say I might have additional exam which QTC. I'm waiting on the VA to schedule it. I'm not sure if I have to re exam for some stuff.