But I have never tracked it and put metrics on, and my gut feel could be influenced by the fact that there 5 vs. 2 days...In reality, it may also depends on your clientele.

Whether you have a mortgage or not will not have any influence on vacancy reserve. 

(They will also determine the estimated NOI under their operating plan and that may or may not influence the price they are willing to pay.)To answer your question, most investors want to know both the CoC return and market cap rate and they are not synonymous.  

Begin by understanding RE basics, the tax advantages, financing, market influences, repair estimates and maintenance to apply to your operation, but the 7-12 year range is mainly due to tax depreciation taken beginning to diminish over time, the greatest advantage is in the early years as appreciation is not considered nor increased rents for depreciation. :)

The deposit/monthly fee has no bearing on influencing behavior in my experience. 

I'd think for someone new, that may be influenced by investor methods, like wholesaling, that they avoid pre-foreclosures where notice has been given.If you're more advanced and skilled in presenting an offer and negotiating without making any reference or even the implication that your offer will provide some relief to their situation and make it clear that it's just a deal and you're not advising them in any manner and do so by showing you didn't target a pending foreclosure, you might go there.The issue is that if the investor doesn't have cash or reliable access to cash, they need to stay away from owners who have received notice.

Before you go too far understand this part of the tax code as it may influence your strategy. you may already know this but I thought it is worth mentioning.

Also the number of bedrooms and bathrooms in the home/unit will influence the water usage to some degree. 

Every unit is different and there are a lot of factors that influence the decision to increase rents.

Am I being a bit too influenced by that?