Hi crazyrov, as far as I know the answer for question (1) is an absolute yes; in fact it is documented on page 28 (FC support):
“Data Domain systems support the coexistence of FC-enabled DD Boost devices together with VTL devices on the same Data Domain system. However, the FC-enabled DD Boost devices must not share an initiator with VTL devices on the same Data Domain system”
Which means you have to use, at least, 2 different HBAs on Networker storage node to connect VTL & DDboost devices.
It did not work on your environment?