I'm looking to subscribe to a service that helps find off-market real estate deals, and am considering options like Invelo, PropStream, Deal Machine, Property Radar, and others.

this can achieve great return but capital Outlay is prohibitive for most (virtually everyone). 

It really helps to have someone local walk the property and neighborhood, but if that's not feasible for you yet I would at least "walk" the neighborhood virtually through Google Maps.Lastly, I would join a Facebook group of investors and landlords in that specific neighborhood.

Consider local vs. out-of-state investing, virtual management, and resources like books like "The Book on Rental Property Investing" and "House Hacking" by Craig Curelop.

There is virtually no way around this, unless you for example are renting a room, and another tenant, in the same unit, has a deadly allergy to a specific animal type. 

You'll experience more in a shorter amount of time vs. starting off on your own.Aside from the team, I'd also recommend joining agent communities especially those that have virtual meetings to role play, accountability, discuss marketing tips, etc.

Virtual wholesaling can be difficult.

Let's say you really want to maximize potential, get in amazing pro photography, maybe some drone shots, possibly a 3D virtual tour.

What is the average age of the machines in the business?

I use virtual assistants from the Philippians or get a gig on Elance to do all that grunt work.