Your property management company can help once you own the property but up until then you need someone good on your side!!! 

I almost exclusively sell bank foreclosures for a large asset management company, and I also do a lot of marketing for wholesale deals.

Which company did you move to, and are you satisfied?

Will the title company put this property under our LLC name, and won’t be required to legally inform HUD/tax authorities. - will it influence property taxes once we move to conventional loan in 3 yrs? 

You will be able to buy from that company just like any other company in Spain. 

Mine are long term rentals (in 2 states), 3 SFH and 1 mult-unit and they recommended a Wyoming Trust over a Holding Company over an LLC for each property.

One risk I could think of is - Even witb a 20 year guaranteed lease, thr company could bankrupt & may put me in a situation to look for a tenant.

I work for a building materials company now and took their online game from Zero to very engaged in the past few years and it's been really fun.

I'm a local, CT based investor, flipper, and property management company owner.  

I am an agent and own a short term rental mgmnt company so am very familiar with the STR rules and regulations as well as the best areas for that strategy locally.