I definitely do not ever want to be under water on an investment so I use:5% vacancy10% Maintenance10% CapEX10% PM.I understand this is conservative but is this still reasonable?

Get rid of wind, water and mold coverages, get less liability.

You almost certainly will be responsible for the water bill.  

updated appliances, pulled up linoleum and refinished floors, added electric panels in units, and added instant hot heat/hot water for units Lessons learned?

When we search for land for investors we use a filter. 

The home was built in 2018 so the major items on the home A/C, roof, water heater all have more than enough life expectancy left. 11/month HOA, 4,000/month CDD.

@Santhi Mani I probably shouldn’t make assumptions but I’m assuming it’s on town water and sewer.

Are the water pipes in the house large enough, or in good enough shape to handle another bathroom.

So, if you wanted to get all of your cost (rehab and purchase) back from a refi, you can't offer more than $430.The property has good bones like I told you :NO Structural problemNO Foundation Problem I will be redoing all electrical , water/sewage , gas and probably the some thermal Isolation .Brand new kitchen , baths and tiles .Open the Layout to an open concept .So my GC estimated based on his visit on the property that rehab cost would be around 100k to 200k . 

When I purchased the property I knew there was a lot of potential to rent this house on a per room basis but the basement was also very unsafe (small windows, no stove, cooking plates improper fire protection etc) but it did come with some nice features such as a tankless on demand water heater (great for having lots of tenants).