1) how long would it take him
That’s an unknown factor.
2) can WM fight him off,
WM should be able to fend him off, or provide a layer of protection for an extended period of time. WM is one of marvel universe premier A.I., and fended of the transmode for some time.
3) wat will Rich be able to do in the meanwhile?
Rich can do what Rich does, and fight his style by wielding the Nova Force at his own discretion. He can prioritize WM to fend off Hank’s takeover.
That’s the beauty of having an auxiliary A.I. up for support. On the other hand can Hank fight, and hack at the same time at peak values?