It depends on a variety of factors. 

If your property is up to par you won't really have many maintenance calls except minor stuff such as plumbing clogs which is more likely to happen and requests to turn the AC up or down which you can do on your phone but other than that pretty hands off.Vacancy depends on location and your Padsplit property score the more comfortable you make your property (mini fridges, tv's, outdoor area) the lower your vacancy rate but you can expect about 10% vacancy factor in a Padsplit friendly area (centrally located, easy access to public transportation).

Another thing about most suburbs is that the property taxes can be brutal which needs to be factored in to your analysis.The biggest thing is where ever you buy, you need to feel comfortable living in AND upon move out, the property needs to cash flow. 

I live in a rural market and this type of issue with technology may not be as big a factor in urban areas.

- How do you factor in the costs of rezoning or obtaining permits, if necessary?

Assorted things.Realistically, on a triplex that's not fully rehabbed, without assuming tenant damages I'd be factoring in roof, flooring, HVAC at minimum on nothing more than a 10 year cycle (5 is safer).

Knowing the Fort Collins market and it's price points a little bit, it doesn't sound like you're capitalized quite enough to get started flipping, especially when factoring in risk (properties in the $300-400k range will be high risk, not good locations).

I’m not trying to rain on anything here but the reality is that measuring Btus delivered to individual units via airflow is by its very nature imprecise - if you want to know why, read on...The size and length of the ductwork is but one factor ( of many) that will yield energy losses while that warm air is being moved to your units.

I don't think the market is a huge factor UNLESS its a SMALL/rural market where filling a vacancy could take longer because of low/inconsistent demand. 2.

They don't even have two-factor authentication (e.g., SMS code on login), or at least don't enforce it for me since I chose to signup using Google.