The conditions are onerous, I think this is to discourage speculation or out-of-town investors who are not invested in a neighborhood in a 'rake leaves, clear snow, mow lawn and lend a cup-of-sugar' kind of way - buying one of these properties and leaving it unoccupied for any length of time would not be a good idea. The conditions (kinda-sorta-owner-occupiers-only) correlate to what the city thinks these neighborhoods need.
Regarding the notion of 'high risk' neighborhoods. See above point - risk is proportional to occupancy. Occupied structure, reduced risk. Rental unit with fallow periods - high risk.
The elephant in the room here is also Race. Race does not correlate to risk or a 'High risk neighborhood' - this notion is perhaps the most insidious and hardest for Capital to overcome - if it ever will be - in which case these supposed 'High Risk Neighborhoods' or 'Bad Apples' will always be labelled as such and avoided. (Incidentally I see this paradigm shift - to be the core argument of the article - albeit approached obliquely)
Regarding neighboring houses - A street in Detroit, if it can go in a downward spiral, typically already has, the city is currently in the process of demolishing blighted structures, and a property owner has a reasonable expectation that if a nearby house has-gone or goes 'galley-west' the city will take it down and offer the lot to neighboring property owners or list it for-sale on the website linked in the original comment.
The taxes correlate to the assessed value of a property, these are slightly unpredictable. However, the city is reassessing property values this year, working under the supposition that realistic valuations that people can actually pay are a better approach. Basically - I agree, lack of confidence in tax-rates is a bad thing, and it's a good thing the city is working to deal with this.