hi kind ser,
I don't want to start a war over here, but some of the things you said are self contradictory and not applicable in real life.
Don't know if you are here to promote realt or you're legitimately looking for real estate investment advice.
You said:
6. I want liquidity, so preferably the real estate should locate in big city. I also prefer at least moderately developed country.
8. I'm not sure if the above scheme work out or the agent can be trusted, so I firstly want to buy small real estate which costs around 10k USD.
In point 8 you said you want to invest $10k, but in point 6 you want big city. I can guarantee with everything I have on this earth, that there is no real estate
for 10k in any big city, not even land. If there is such thing, it most likely comes with few hundred grands worth of debt. Perhaps your definition of big city differs from mine.
While I can't answer for the entire world, most likely what you're looking for doesn't exist because it's too specific.
example:
Rent should be paid by bitcoin with the amount of fixed local fiat currency (for example, 400 USD per month). The rent should be collected by appropriate agent and converted to bitcoin.
the above, if paid in FIAT or transferred to bank directly to you shouldn't be a problem since you could convert to btc yourself. If someone does the conversion they'll most likely take service charge for the work done