On the first:
I think that the Virus can be configured as a 'VST' plugin, which makes it very flexible and usable as an insert effect. The HD does not have this functionality. Someone on the board may have a clever routing trick but that easy 'drop it in anywhere' VST functionaility is not available.
On the second:
That really does not sound right.. I just did a search and couldn't quickly spot anyone else with the problem either. Start off by changing the Wah battery and getting some other cables to check with. If that does not help, you could try hooking the Wah into the FX Loop on the HD and placing it first in the effects chain. See what that does for you.