IMO killeen is a solid investment. just have to watch which areas you are getting into. there are some pretty rough areas near fort hood but killeen is great because it is close enough to austin and people commute from there to austin as well. with fort cavazos near by and the new samsung plant coming online in taylor, it is a solid choice with steady demand for MF.

Their new online system is really confusing, and I have had to call customer support for help each time I needed to wire/ACH funds because I could never figure it out on my own (and their customer service chat box isn't set up yet). 

A lot of that is referral based or people find my site online, organically. 

The property would be in a C+ to B- type location, with cash flow as the main objective and appreciation second (75/25 split).

Quickbooks online could work for what you need.  

I don't care what anyone online says if you live there and have tenants at your home it will be a job. 

A good tip is to reach out to contractors, visit local supply stores, and check out online resources for cost ranges.

When I did an online search for commercial multifamily lenders, most have a minimum lending requirement of $1M and I don't need that much. 

Based off the information you provided, it sounds like there's no issue from your end.In the future, you may want to include something in the lease agreement that outlines objects that may be stored on premise.

Are there any good resources online to be able to get an idea of average monthly/yearly expenses like utilities, etc. for a given zip or city?