I ran into a few issues with some of the repairs (I had to replace all the pipes as well as the furnace) but due to the fact that I expected the unexpected, I kept a calm game face and I kept moving forward.

As I pointed out (about the roof) there are going to be many unexpected expenses that will occur over the next several years.

Be sure to add 10% to estimated rehab for any "unexpected" costs.

I only only need 1, so if I get an electrician, you for instance, you could install it and put everything inside the unit in order, outlets, switches, etc,.

Section 8 inspected it and said it was good to go after we swapped some un-grounded outlets out to 2 prong. so for 4 bucks and a re-inspection we were in.

You can HOPE that people believe in karma and they won't just put new outlets on old wiring, but you'd be surprised at what is concealed.

We had to do a lot of small cosmetic things (replacing the flooring, changing the electrical outlets from old yellow ones, light fixtures, popcorn ceilings) and it is still a work in progress.

Based on my research here is what I am thinking I should do.Remove the current drywall | Add Safe n Sound Insulation | add 1lb MLV |Sealant around the walls and outlets | Fire wrap around the outlets then add 5/8 drywall. 

Remember, real estate investment involves risks, such as reliance on tenant payments (like you mentioned) and potential, unexpected, property maintenance/repair issues.In conclusion, both strategies have their merits.

We have about 11k in cash but would like to keep that so we can cover any unexpected costs that come our way.