Even so, given the option to live forever, I wouldn't forgo it so that you could avoid said dread.

Regardless, I don't think that your reasoning about people being set in their ways is valid given significantly longer life or healthspans. A lot of existing conservatism is from people with families (don't rock the boat so I can focus on raising my young!) and people who are suffering the ill effects of aging (don't rock the boat so that I can retire in peace!).

The first group will likely diminish if we have longer healthspans (or else we'll run up against the barriers of overpopulation). Even if not, longer healthspans mean a longer period where people are neither raising families nor mainly preoccupied with living with advanced aging. As a result, I don't think the effect you're describing will be a significant one.