I understand I cannot legally require them to respond, unless the notice specifically requires it, like for instance, a notice of entry, but it's making it difficult to manage the property, and I'm not sure how to proceed.

The town of Speedway itself is difficult because of the price points, but it has a really good ROI. 

I do not know him, but the path he is leading you is a difficult path    Note difficult does not imply impossible; there are people who are successful with S8 housing    In my area s8 is so undesirable that they write laws trying to make it challenging to not allow S8 tenants.  

In terms of STR it seems that in the really strong markets (Lisbon, Porto, old town Ericeira) it is difficult to get the AL licencing.

As mentioned 90 day limit, which makes it difficult, and wuite pricy to get the STR certificate from the city. 

What you want is an agent with experience who knows how to negotiate, watch your back, navigate difficult situations, understand contracts and law, provides an objective cross-check, etc.

Then some people are frozen with fear of regulation and who don't do any deals or stick to investor loans.It's not actually difficult or scary to get it right.

As someone who's spent the past 20 years building software to ingest massive amounts of random data, the short answer is, it's really difficult to get accurate contact data.

I would focus on getting a solid job/career then going into a house hack. 

I was a college athlete whenever I learned about BiggerPockets and really started my investing career.