If the Convention proposed anything the States disliked, then the States could reject the proposed amendment and so the proposal would not become part of the Constitution. The last two amendments proposed by the Congress (Equal Rights Amendment and District of Columbia Voting Rights Amendment) were rejected by the States, so the States are certainly not rubber stamps regarding proposed amendments.
Finally, there's no way the Convention would be able to impose amendments or a new constitution. Any such attempt would be viewed as illegitimate and would destroy the Convention's credibility. Any thought that the federal government, the States, or the People would acquiesce in such an act is laughable.
Thank you, much. I tried to put it in “easy read”....you make me a piker. I shall endeavor to follow suit.