Would you pay mortgage, insurance, and water through the business account, then personal expenses like electric and cable through your personal account?

Being a newbie, I may have some numbers that are a bit off, and if so, feel free to challenge them.So I have seen people assuming Capex of 5-10% of the rent, which would equate to $85-170/mo for a 1,500 sqft 4br/2ba with no garage.When I run the numbers though, I get: $328mo, or just over19%, so I wanted a sanity check.I calculated the following (installed costs):Water heater- $1,000 per 10 years =$8.3/moDoors(8int)- $2,400 per 25 years =$8/moCabinets- $5,000 per 20 years =$20.8/moCounters (gr)- $4,000 per 25 years =$13.3/moBacksplash- $2,000 per 25 years=$6.7/moFridge- $700 per 20 years=$2.9/moOven- $500 per 20 years =$2.1/moMicrowave- $300 per 15 years = $1/moDishwasher- $400 per 15 years =$2.2/moGarbage Disp- $200 per 10 years=$1.7/moWasher- $400 per 15 years=$2.2/moDryer- $400 per 15 years=$2.2/moSiding- $12,000 per 25 years=$40/moA/C- $5,000 per 15 years=$27.8/moDoor(Fr)- $2,000 per 30 years=$5.6/moDoor(Back)- $750 per 30 years=$2.1/moRoof- $7,500 per 20 years=$31.3/moTile (500ft2)- $6,000 per 20 years=$25/moLVP(1000ft2)- $5,000 per 10 years=$41.7/moPaint (int)- $4,500 per 5 years=$75/moGutters (200ft)-$2,000 per 20 years=$8.3/moI would probably need some $ for driveway, exterior paint and landscaping as well, but overall with what I have included, it seems 2-4x more then most people even budget for.

Walk through with a GC or jack of all trades handyman and ask: how much for a full repaint, how much for a new roof, how much for drywall patching, water heater, etc.I reserve for my capex and repairs separately, because they handle different items. 

I have been relying on unemployment benefits to help keep my head above water.

Make sure you include water/sewer, lawn care, snow removal, admin/professional fees.

So you have the budget to replace AC, hot water tank if and when they go out and you have the budget to do a light cosmetic upgrade to raise rent rates a bit when you're ready. 

I'm currently negotiating w/ seller to reduce price to between $85k to $90k based on the major rehab costs.Total rehab costs: $31k get it rent-ready.Annual prop taxes: 2,237.72Total rent: Between 1,010 to 1,250 per month for both occupied units, depending on how bad the recession will become later in 2020.Lawn trim, snow removal, gas, electricity, & water: Tenant pays.Property management: I assume 10% of rent, so $101 - $125 a month.NOI per year: $8,670 to  $11,262.Flood insurance: None.Home insurance: $556/year paid outside of escrow.CAP rate: 6.46% to 8.6%.

By then i should have a yearly cash flow of: 1851,- That is one third of my cashflow gone, but will still keep my head above water. 

The combined rents collected covers my mortgage and water, im loving that.

Many of these items are trivial to fix such as missing smoke/Carbon monoxide detector, water heater not properly strapped, etc.