Canadian Debit in Harare (and other currency q's)

Hi there
I may be moving to Harare in October for a contract for six months.

The Canadian Embassy website says that Canadian debit (interac) cards do not work in Zimbabwe however I saw on the thread that there are international banks such as Barclays and Standard Chartered.

Are there any Canadians out there who has successfully taken cash out of an ATM recently? If not, what do you do for finances there?

Also, what currency do the ATMs dispense?

Is it true small billed currencies are low and I should bring a bunch of $1 and $5 bills?

Are American dollars used the most? Do all the currencies criss cross in change (rand, euro etc?) how does that work when purchasing goods in the market? I am terrible at math.