I dont think it was necessary ,Palpitine wanted a Command ship that would strike fear into everyone who saw it, a flagship that would be able to keep everyone in order but all it did was make a prime target and a way to drop imerpial morale.

I mean, Tarkin wasn't exactly right, but the Vong are a thing, so

No, it got blown up and made Rebel recruitment skyrocket. Like Thrawn said, it would have been so much more worth it to strengthen the navy and army

If I were Emperor Palpitine, I would have spent the money on creating propaganda and indoctrinating children to be fanatically loyal to me. I would also recruit a force sensitive thought police force to ensure anyone who did not buy into the ideals of the empire could be identified and corrected.

Rebellion cannot exist in a society with no free thought.

^I think you'd have to push the release date of ROTJ back a year to do that

I believe so. There was acts of rebellion across the galaxy and with a weapon like the Death Star, I could show the galaxy the consequences of their actions. Alderaan was that example.

I'd say yes. The Empire wanted to build something to install fear and dominance throughout the Galaxy.

I mean probably not but I think it's a silly idea. Plus a planet as a base is a neat idea so I guess yes

It's documented that Thrawn didn't think it was a good idea to do the Death Star right? He favoured a stronger military than one superweapon.