With an existing loan in first position most hard money lenders won't make you an additional loan. 

I have lease agreements for all the properties and they are all cash flow positive but I am worried that a lender would not look favorably on the complex situation with my seller financed homes as they are not outright mine on the deed etc....

His or her initial feeling/position on your request.

In my position a property manager is a must and am very excited to be in the process of hunting down a good deal for my first rental property 

I would like to keep the property and turn it into a investment property but it does not look like it will cashflow positive once turned into a rental.

I believe HA still has the option to wait 24 hours before approving them.As a Premier Partner you have access to phone numbers during the inquiry phase.I have seen where others have provided feedback form other booking sites and I have not seen any positive feedback on them.I am even getting bookings through Expedia now since they own HA.

Have you had any positive, or negative, experiences with seller financing deals in the past?

You are probably looking at about $150 positive cash flow per month long term.

You may want to reconsider your ultra conservative investment approach in order to grow and actually achieve positive cash flow.If you are buying homes worth 50K or less and renting for $850 + per month you are not doing as badly however you should try to find a way to pull all your dead equity especially before the markets turn and you end up losing it all.Paying off rental properties is not investing it is hoarding of cash and is extreamly expensive.Just food for thought

Should bring in $300-$400/month positive cash flow.