Impeachment is going to be interesting; it requires a 2/3 majority that ZANU-PF doesn't have. The new ZANU people have been sidelining opposition since the military takeover turned out so successfully...but if they want to keep the impeachment process nice and constitutional, maybe the opposition will have some leverage after all.
ZANU-PF have 196 seats, which is 75.6% of the seats. Well above the 2/3 majority needed for impeachment.
2/3 in both the House and the Senate. ZANU-PF is a bit short on the Senate, with all the tribal chiefs and everything (they probably support/are members of ZANU-PF, but they are harder to whip, I would assume).