If you at least factored in another 5% for Capital Expenditures (which I still feel is low) then maybe you can get by with 5% for repairs, but you currently have no money being set aside for big expenses like roofs, water heaters, furnaces/ boilers, siding, any paving etc..

I'm very unfamiliar with water that is sourced from a well, anything I should be weary of?

This lot includes a foundation stubbed for electrical (underground)/plumbing/sewer/water etc. the former property was deemed a total loss in a house fire and the prior home owner cleared and stubbed the foundation (slab on grade).

one water heater replacement blows your cash flow for almost an entire year (although maybe you've accounted generously for capital expenditures like this). 

Friend of mine told me that the HOA fees with a condo of his includes utilities such as sewer, garbage, and water.

I am in Portland OR and this is right on the water.

I have heard of cozy and tellus, and other recommendations?

Again, you'd want to refer to the lease to see if you are allowed to charge TICAM, which is sometimes referred to as "additional rent" in the lease.NNN expenses for a landlord could include landscaping, parking lot, roof R&M, HVAC (based on the lease sometimes the tenant is responsible for up to a certain dollar limit in a 12 month period and then the owner is responsible for above/beyond that amount), exterior water proofing, management fees, general & adminstrative, etc. 

For example I didn't need the 20ft ceilings or 3car garage or water fountain in front. 

@Pedro Sanchez I would look into Cozy.