She took on the property management side for a reduced rate as I purchased the place recently through her.

Most mortgages are fixed rate.  

Interest rates will skyrocket, as inflation comes back. 

One of the properties has about 50K in equity built up with a low interest rate on a 30yr loan. 

Yes that can be an option but at the moment right now i have a deal in the works where i would need more then 50K to be able to make the numbers work I also recently went to a random bank and got a LOC for up to 50k at 11.5% interest rate with no fees.

How would most sellers react to a 3-4% interest rate?

My friend wanted to lend me the money for my investment property at the same interest rate as Guidance and I would pay him a fixed rate monthly and we would both own the property until I pay it off. 

So far, I paid below market rates because the building was severely under managed. 

Also, to what degree are people reacting to the new insurance rates?

Its clear that we will need to find a way to increase the occupancy rate, to be able to make profit.