Are there any tried and true/ industry standard sites, forums, etc. where those looking to avoid capital gains look for investment properties?  

Also, some municipalities require that the property be your primary residence and that you live on site to manage.

Mostly I'm just trying to keep track of things for my own purposes to make sure I'm getting what I expect and the properties are performing the way I expect. 

If so you can still use the STR sites like Airbnb/VRBO and just have a 7 night minimum. 

We try to make sure the seller knows within 10-15 days max if we can perform or not, so they always can have another option.

Also, if I do, is there certain information that I should be gathering/evaluating, and certain questions that I should ask of the people working at the site to make the most of the visit?

You need to know the market well, have enough reserves for inevitable expenses, and closely monitor the asset’s performance.

I work in Denver (as well as Colorado Springs), and that city is performing very much like Ausitn.

So this site has been one of the most useful resources I've found.  

I’m always asking how much a project costs when I hear folks talking about doing renovations, and I ask how their contractor performed.