My initial thought was that I'd like to have '5 doors' to buy and hold with the long term goal of supplementing my retirement.

Great to supplement it with REI.

They also will not allow the tenant to supplement the rent out of their own pocket.

Supplementing a tenants rent will help to keep them longer.

Think layers that you add as you grow - each supplement the other and cover you better, but you still need them all.Only you can determine what is your risk threshold.

I have a good idea of how I want to get there, I’m just curious of other people’s paths to get there.My original goal with real estate was to provide additional income for retirement; have a couple paid off houses and help supplement retirement income from my 401k, social security (if it still exists), etc.

You might find that kind of service with a bigger firm for which you'll pay accordingly ($$$$+ annually).You need to learn yourself or pony up the money - here are some books to get you started on this:for accounting and taxes - Every Landlord's Tax Deduction Guide 15th Edition (and you can supplement that with Deduct It!

I have good capital and a supplemental income from a property I inherited in Virginia.

I work full time and like many of us here, I am looking to supplement my income and eventually not be 100% reliant on the 9-5.

You could prolong your financial suffering and continue to supplement his rent but your best option would be to go directly to $1550 and stop losing money.