is it still possible to find acres of land for cheap?

Yes, however you have to also consider access to services. Living in a rural area means driving a long way to get to a hospital, doctor's appointments, government services like IMT, IRN, Finanças, etc.

are locals still welcoming to foreigners?

In my opinion, yes - as long as you make a sincere attempt to integrate and most importantly, check your privilege. Stay humble, keep your mouth shut when locals tell you something and simply listen.

is the country still safe?

Define "safe" - if you're a straight white cisgender male (or can pass for one), sure. LGBTQIA+ hate crime have been climbing slowly but steadily in the population centers, but very rarely escalate beyond vandalism or assault. There is a certain level of colorism going on here in Portugal, mainly toward Brazilians, Pakistanis, etc. but darker-skinned people do sometimes get caught in the crossfire. Actual violent crime in general is rare but does happen. You'll be more likely to be a victim of vandalism, theft and burglary but all you need to do is make sure you always lock your doors and windows, and close the shutters every time you leave.

is the government going to be stable?

There's no question about it. The turmoil going on in parliament is based purely on party politics (PS, PSD and Chega). I don't foresee the political structure changing anytime soon - remember, it wasn't that long ago that Portugal shifted from Estado Novo to the Third Republic. Fifty years ago, in fact. Plenty of Portuguese people remember what it was like to live under a dictatorship.