Lucas didn't do the clones justice by treating them as nothing more than CGI cannon fodder in the prequel trilogy. An entire other team had to create more (and better) stories to explore the obvious moral dilemma of creating clone soldiers enslaved to the Republic's MIC.
deleted by creator
It being a 2nd death star is actually genius and realistic if you ask me. They still have the plans. Just make a few adjustments to get rid of the now obvious vulnerabilities and you got a winner on your hands! The thing blew up a whole-ass plane,t probably more then one, it's a proven concept and there is no need to iterate on it beyond making improvements here or there.
That the emperor uses it as a trap for the rebellion and risks it all is overconfident, sure, but since it does have a shield and functioning weapon, it's not that overconfident. Even that he's there is explained because it's all a trap for Luke.
Meanwhile the EP7 weapon just works on completely different principles that seem to work differently then the rest of the setting. Like, imagine a fully powered original trilogy empire having that weapon, it would just be over.