From my research a business credit card does not impact your personal credit should I have a high credit utilization rate. 

Is this the only feasible route to utilize retirement savings?

We're adding a clause that if they go beyond $160, they're defaulting to a slightly lower rent + paying they're own utilities (I saw that past bills for a year were around $70 average) So far we have 3 vacancies with one filling in this month and a good lead.

Purchase price: $760,000 Cash invested: $60,000 House hack, I live in one of the unitsIncome ~ $4,250Mortgage ~ $4,550PMI ~ $425Flat fee utilities covers everyone's utilities30 yr conventional fixed at 4.5%, 5% down owner paid closing costs = $38kMy unit would rent for $1400 easily (2br/1ba) making total income $5,650Once PMI drops, mortgage will be ~$4,125Repairs were upgrading electrical, fixing drain, fixing boiler, new shower in my unit.

I had a lot of real estate investing under my belt, but still utilized a partner for my first deal.

This is based on recent sale of exact model in my community$889 monthly mortgage payment includes tax + insurance (son is paying this + utilities)850, 834, 824 credit scores No bad debtNo car payment and driving my current car until the wheels fall off.$250 per month for rent.

The idea was to utilize the BRRRR methodology to refinance my current house to the appraised value and use the cash to purchase another house.   

Some may prefer to utilize the convenience of technology while others want to maintain personal relationships.

Sounds like your rent is to low, I would double check what market rents are.I would get all the utilities in the tenants name.

My memory is that someone paid the utilities before I took possession but I can remember for sure....maybe I did paid them.