How far away is this to the closest town? When you create a techno hub, people will need accommodation and access to Mall's and entertainment and shops etc..

There has been several attempts by people to create their own sovereign area within the borders of a specific country and even in international waters and these people failed. The last guy fled the country when they wanted to arrest him for creating his own sovereign floating house in the middle of the sea.
https://www.businessinsider.com/bitcoin-trader-chad-elwartowski-thai-navy-destroys-floating-house-2019-4?IR=T The town, I don't know, but they mentioned that CITY Kaunas is very nearby (up to 15km away). Second biggest city of Lithuania, some say it's the "Heart of Lithuania".
So in the worst case scenario you could even walk there.

They can only raid something if they know where it is. So try to find a way to keep the location secret. Or hidden in plain sight, or something. And have proper physical security, armed guards or something.
I mean, we all know where the bank is, but you can't just try to raid it because it's being guarded.
I'm all for these kinds of bunker hubs, people should do whatever they want to do without having to answer to some bigger boss just to get their approval. But I'm not sure this kind of location could really survive big brother if Uncle Sam or thereabouts decided to ask Lithuania to give access. How is autonomy (if not sovereignty) guaranteed?
Forget everything else, make sure you use Bitcoin first (if not exclusively first),
P.S. You should move this to Projects! I would, tends to get a lot more interesting people looking there, Marketplace doesn't quite seem to fit this project;)
Thank you for your advice, ideas and help. We found many wonderful friends and partners on the forum. Now we have created and launched a joint project of Social cryptocurrency exchange Yuppex.com together for all crypto traders worldwide. After COVID-19 pandemia, we will use our complex of real estate as a place for pleasant work, meetings and events. We transferred the property to this project. It is our Yuppie contribution to Yuppex. If you have any ideas, welcome. Our new forum topic of crypto traders social network Yuppex is here.
https://bitcointalk.org/index.php?topic=5259469.0
https://youtu.be/CGeGaLfjokg
Special thanks : Lapatai, Dabs, DaveF, buwaytress, Kakmakr