How much do you typically pay for property management (% - please specify if it's on base rent or gross rent including NNN reimbursements)? 

However, we do have many maintenance and repair cost this year, as our property management always does repair for us without asking for approval, and then we got surprise and pain at the end of each month when they ask us to reimburse the repair cost, and this is a major reason that drives us to switch to different companies.

I think total rent forgiveness is too much unless property owners are reimbursed somehow through mortgage forgiveness or deferment, but perhaps some combination of all the good ideas already mentioned is in order.

Or if you take cash out (even if you're calling a reimbursement of expenses) the IRS will say it is profit first.The answer would be to do the rehab in such a way that there is a lien attached to the property that must be satisfied before you can sell it. 

If there is sufficient equity in the property you would also be entitled to be reimbursed for any property taxes you pay. 

You'd need to purchase the land on your own (through whatever financing you deem best) and then you can get a construction loan that is both horizontal and vertical to cover the build and reimburse the land purchase.

Of note, I believe the lower unit will mostly be 1 adult and 2 of her children, and the other 2 children will only be there part-time.Do I just keep the electricity/gas in our name and have the tenants reimburse us each month? 

The only people I let do that now are inherited tenants who have been paying their own water for years.For subsidized programs, you can get some utility reimbursement for what you're paying - also often for providing appliances!

I have another individual to which a similar occurrence has happened, and there are a few other local individuals to which he never finished two properties locally, he (well I did but he was supposed to reimburse my expenses) started three other properties.. 

My tenants paid each month's rent and reimbursed me for the utility bills I paid.