After some research, I'm thinking it would be a good opportunity to proceed with the offer and to set aside the "free" money for use for repairs/renovations and holding costs to have some extra cushion.There seems to be much debate on the use of credit cards in real estate investing, but considering my circumstances .. 1.  

She/he should be able to provide you with a chart of accounts to choose from, such as Repairs & Maintenance, Supplies and Amenities, etc.

This isn’t really a big deal though.Rent payments can be abated over unresolved maintenance issues and tenants failing to abide by S8 requirements.Many S8 housing commissions will not hold tenants accountable for damages they cause (tenant is supposed to repair or lose their voucher).

Also, is he entitled to the security deposit (minus any repair expenses)?

They are not allowed to do any repairs or modifications, none, without written consent.

Identify necessary repairs and improvements.2.

Can I split the cost of the plumber and tank repair on both tenants, as they both clearly were using the wipes and it's very hard for me to believe they were NOT flushing them.

But now I have to make part of the lease and get a signed form.I maintain the property and have emails and texts with the Tenant's requests for maintenance and immediately respond and have acknowledgment from them when the maintenance flks arrive to do repairs. 

The tenants may not like the timelines or outcomes of the repairs - part is on back order, they have to pay for the repair due to abuse, the owner chooses to repair instead of replacing.

Here is my short list:Overestimating the After-Repair Value (ARV):Investors sometimes overestimate the future value of a property after renovation.