The multi-stage furnaces use extremely expensive circuit boards and fans so repair costs will be high.  

Will you be taking on investors and using their money to fund loans (i.e. arrange the loan and make a fee), arrange fractionalized loans, hypothecate loans you’ve made, perhaps start a mortgage pool, loan your own money, broker NPN's, or some other strategy?

I've found that students look for and arrange for housing 6-9 months ahead of their need in most cases.  

Now that you have worked on different payment arrangement styles you have opened yourself up to issues.If it was they pay each month and it's late after the 5th then it makes it simple.

I pointed this out to her, and she immediately filed a cancellation of contract with that management company, and arranged for me to pick up the keys.

It is a take it or leave it business arrangement.

I'd love to arrange a viewing for the property, but before can you answer these few questions first, so I can make sure you're a good fit: Why are you looking to move to this property/neighbourhood?

For example I use google voice and plan to arrange repairs, but now that I have 12 units with mostly Spanish speaking tenants I would like to systematize the process of them calling or emailing a 3rd party that will send me maintenance request, which may eliminate the communication barrier???

I would choose one or the other, but not necessarily both.For example a boarding house arrangement you would typically rent by the week, similar to a hotel.

If you absolutely refuse to install a separate hot water system, then at least address it directly with the tenants and set up a rent offset for the tenant paying the hot water of another tenant.Although I can tell you from experience that this sort of arrangement seldom works long term.