If you're making 4.5% now, you'll pay more servicing the debt on a HELOC.

I'd advise you to pick a service that partners with the Campaign Registry to let you register a phone number in order to comply with TCPA and benefit from optimal deliverability.

So typically depreciation and expensing of costs usually happen on the placed in service date.

Hence you needing to retain an Architect and have them do due diligence into the feasibility at which part of their services would be checking what is able to be built in compliance with the applicable jurisdictions. 

To qualify as a real estate professional, a taxpayer must meet both of the following criteria:Taxpayers perform more than 50% of services in real property trades or businesses in which they materially participate.

You will file a 990-T and there are plenty of services out there to help with this. 

Since I've never used their services, I'd like to know what their experiences have been with them.

Somehow I didn't notice there was an educational part of the service. 

I pictured a management company that handled rent collection, cleaning service, etc..

Make sure that the corresponding lender or broker you are working with has a loan servicing company that is non-reporting.