I found this realtor by simply talking to lots of different realtors and requesting their assistance with my situation.

Then surprise her with request to have her show you her kitchen, bathroom and living room. 

Can anyone recommend a third party phone/answering service that can field and respond to maintenance requests from tenants?

She did request I change out an outside light fixture. 

Because you have one of them on M2M, that gives you the opportunity to raise rent, request an application from the tenant, put your lease in place with your terms, etc. 

The tenant is requesting the return of their last month's payment and security deposit (equal to one month's rent).

Then it was suddenly frozen one morning and, after an email to the address zillow provided, a voice message to the appropriate phone number, and a form filled out with exactly all the information they request, we get no response for almost a full business day.  

My understanding of how section 8 works is you request a rental amount and then they tell you how much they approve? 

for my rental property which is vacant right now, i see requests coming for a year lease for corporate lease or for AirBnB-ing... 

If the HELOC amount you're requesting is relatively low (often below $100,000), lenders might waive the full appraisal.Drive-By Appraisal : Instead of a full interior inspection, a drive-by appraisal involves the appraiser evaluating the exterior of the property only.Desktop Appraisal : This type of appraisal is conducted remotely using data and photos provided by the homeowner or real estate agents.Based on the little knowledge that I have about stuff like this it sounds like you need to connect with existing lenders in your network or find new lenders in your network that have programs aligned with your goals.