That's unusual and it would be very difficult to find a passive investment like that.Also direct control means I know exactly what's going on.

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

Yes, Spain is one of the countries in which banks will lend to non-residents (they generally don't) but Spanish banks are much more conservative than US banks so it's more difficult to qualify, especially if you don't earn W2 income.

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.

If they find out they can cancel your policy (which makes getting a new policy more difficult) or if you have a claim they could deny coverage.

when I used a capital gains calculator online, if I put zero money down and put the 2 loans, the cap gains is a lot lower than if I just recorded 1 loan and entered the money from the downpayment loan under cash.

It's very cheap and not difficult to maintain bond/license/insurance.

Very difficult to see in the pictures what has been built in a month.

In all honesty, it will be difficult to collect anything from the tenant after they move out and you cannot force them to stay.

It is harder, more difficult, more risky to wholesale without a license.