Interesting topic :)

Well, in the first place it seems to me that we are not likely to achieve what you call A-mortality (that is, life expectancy of several centuries) anytime soon, short of some unexpected miracle in medical science. I mean, we've raised life expectancy by what 20 years since the middle ages? (which don't get me wrong, is amazing enough) There is no indication I am aware of that this raise will be exponential.

As for the other questions you raised though, imo you basically outlined some of the key battlegrounds of our time :) For me whether medical technology will be withheld from poor people is not a question of speculation but a practical contemporary concern - we today will be part of what determines the answer. So we need try to fight the forces that even now seek to reserve healthcare for the privileged - as you say, we have succeeded before in history. Likewise, conspiracy theories as you noted is a relatively recent problem (as in it scaled to problematic proportions recently). Honestly, I personally find it unthinkable that we can suffer such thinking to continue to exist in the current scale until such time as A-mortality is possible - we need to fix it and fix it soon.

As for whether I would like to live an extra 100 years (over the current average life expenctancy, I assume), I can only confess "yes". Though I'm not sure if that would necessarily remain the answer if I became wiser :P