This reduces my rate without buying it down.

My concern with the home equity loan strategy is I'd still have the first home mortgage, the equity loan, and a new mortgage (albeit reduced from the down payment).

@Andy LanyiGood comments on how to reduce tax bill. 

Real wealth is built over time with consistent effort, even when things are difficult.Increase earnings, reduce expenses, save, invest.

Their inflated costs and reduced services make them an unattractive option.

Unused contingency funds, unless they were received directly from the borrower, must be used to reduce the outstanding balance of the renovation mortgage after all of the renovation work has been completed and the certification of completion has been obtained.The loan is not re-amortized.Draw Schedule:The HomeStyle program has a maximum 4 draw process.The initial draw can be up to 50% of the total project and can be for materials for the project.The final draw will be at least 10% of the total project as retainage and funds will be released upon receipt and approval of final inspection, Certificate of Completion from Appraiser, signed All Bills Paid Affidavits and Lien Waivers.Additional Draw Information:Ø Signed Draw Request by borrower and contractorØ Signed All Bills Paid AffidavitØ GMG review and approve the draw request and will release funds for disbursementØ A check will be issued in the name of the borrower and contractor and delivered to borrower via USPSØ An inspection of work to date will be performed at 50% completeFinal Draw Information:Ø Signed Draw RequestØ Final inspection/Completion Certificate will be required for release of final fundsØ A Title Update showing property free from lien or encumbranceØ General Contractor’s Lien Waiver AffidavitØ Affidavit of Completion GR will review and approve the draw request and will release a check in the name of the borrower and contractor.Change Orders and Cost Overruns:Changes to the initial plan are not permitted unless prior approval by Guaranteed Rate.

A cash purchase, added to my portfolio, reduces my levergage ratio on my real estate portfolio, but does not bring it to zero of course as I am not paying off existing low rate mortgages on rentals. 

This streamlines operations, reduces administrative burdens, and retains liability protection.

Try to reduce the number of problems you can think of to a manageable level, or instead of a 5 bedroom place maybe go a little smaller with a 4 or 3 bedroom that is generally more manageable and not pack people in like sardines.  

Meaning any of your Helocs can be closed or reduced at any point if any of your banks feel you are over leveraged, miss a payment, credit score drops, even by mistake it happens all the time.I would get rid of the Helocs and put some cash in your bank so you can use that versus a Heloc.