I owned a timeshare unit in a development with many unsold units. 

If so requiring them to use the system could be construed as extra rent.Some people like using non-online payments.Providing some form of a receipt for rent payments is generally a good business decision and if Cozzy does that it shouldn't be a problem.

Having someone experienced in real estate give me some extra tips is always great

I'd wait until you have the money set so that you don't have extra moving parts.

It's possible to turn a profit if you buy a distressed property and "flip" it to yourself.I bought a 3 bedroom, 1.5 bath with garage conversion as extra living space. 

You say you can afford the mortgage even if the other unit is vacant but that you don't have extra cash for the other expenses of being a landlord.So...instead of buying a single-family home instead, can you buy the duplex, keep up with the mortgage, sit on the other unit for a while until you've saved up some cash, then rent it out?

Municipalities will Not be common buyers for vacant land....not sure how you came to that conclusion.The vast majority of vacant land you can buy this way will have No value to a builder.....there is a reason people so often let these properties go to tax auction and it would be very difficult for you to determines the paths of growth and what would be desirable to a builder/developer.

I'll work extra, I'll miss out on my family for a few years if it will pay off within 5 years or less, not if I'll not see the fruits of this for 20 years for.retirement. 

I keep a bucket full of the extra slats from when I shorten them to fit, just in case someone breaks one or a dog chews on one.

It was really the only "extra".Do you have garages?