Is that red flag that they did not provide their SS#s?

If you're saying you're owner occupying a unit and it's 2 hours from where you work in the other town- it may throw up red flags. 

This is what I advise all my friends to do to list their rental property if they don't want to spend the money on listing with a real estate agent- Go to Lowe's and in the isle with the typical red and white "For Rent" signs, you will find a blue/green sign by Registersigns.com for about $15... you can then go on their website and upload photos and a property description - the website links your "listing" to the majority of the online real estate sources automatically - this is the most widespread marketing net you will get without listing it on the Multiple Listing Service (MLS) - If you aren't getting any activity...

Every time I factored in Association fee increases not to mention everything else Greg S mentioned, I was going in the red in about Two to 3 years it seemed.

That is a big red flag for me. 

Renters who deal in cash are a big red flag for a lot of landlords.

What are some positives and red flags that you all look for when assessing a specific market?

There are a few red flags here, so I'm proceeding cautiously. 1) the unit is a 3 Bdrm, but son says only the father would live there; 2) the unit is $1,300/mo, $400-$500 more expensive than 1 and 2 Bdrm units currently on Craigslist; 3) the son’s email is in poor English, like it’s not his first language, but when I spoke by phone with the father, his English was perfect.

Daily i'll get one response per day if lucky, the main question i have but does anyone has a ad service they've been using or posting strategists to post and not get flagged or post multiple ads per day at certain time as well so i would never be at my computer ?

It can be a red flag: trying to move before pending eviction hits record or they didn't give proper notice.