However, is cold calling Tax Delinquent leads an efficient use of one's time, or would you just send them direct mail? 

She should get you to closing as efficiently as possible.  

And nobody believes me when I tell them it's more cost efficient and comfortable to just raise it up a few degrees, instead of shutting it off when they leave. 

These are some initial questions you may ask and from there you will kind of know if they have much knowledge in the area, how efficient they are and if they know what you are looking for 

If you are rolling the rehab into the loan it may be more efficient to roll it into capex than to have higher operating costs for repainting. 

I drew up the floor plan of the upstairs for my personal space and efficiency apartments.

and system would be more efficient, but it will cost quite a bit more. 

- If you refi to invest in mutual funds make sure you do it in a tax efficient manner...You could easily pay just as much tax on the mutual fund side of things as you would on the RE side... and at least with the RE side it is easy to predict the taxes. 

What have you guys found is the most time efficient way to search and analyze deals?

Most full time investors find apartment buildings and commercial properties more profitable and more efficient to deal with.