Unless you think you can trust the existing regime not to do what it says it will do, this is the only way to stop them from gaining the bomb and using it against Israel and the US. Will Trump succeed? I don't know. If Trump fails, the world will be at greater risk.
As far as regime change, Trump is calling on the Iranian people to do that. If they don't rise to the occasion, then this was doomed to fail no matter what (and we will have to bomb them periodically going forward). You can't give democracy to people; people must take democracy. If Iranians don't want freedome, it cannot be given to them.
Paying the Iranians not to do what they repeatedly say they will do (wipe Israel off the face of the earth) is just sending money to extortionists, over and over again, in the hope we can trust the untrustworthy.
Trump has the balls to do something no other president had the balls to do. Is the right move? I don't know. But, at this point, we should all hope he succeeds. If the Democrats succeed in holding Trump back at this point (as many of them are demanding Congress to do), then the ayatollah-regime will just be emboldened, and the world will be very much worse off...especially those Iranian sexy ladies you lust after.