FWIW, we appoint a manager to deal with the tenants and arrange repairs. He gets half a month's rent for each two years lease.
We approve repairs by email or WhatsApp, and reimburse the agent for those repairs. We pay the rates and management fees directly.
For signing docs, a POA works but we've just relied on courier for documents which require original signatures (new leases + the annual property tax return).
If you are thinking about selling while abroad, speak to a conveyancing lawyer to make sure the POA is in a form which will be acceptable - best if they prepare the form for you to make sure there's no stuff ups. Obviously, the appointed attorney needs to be someone you trust and the solicitor should be instructed by you to deposit the sale proceeds directly into your account.