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Air France and Continental are partners in the SkyTeam alliance, at least for a couple more months.

Your bags should be tagged at check-in by the AF agents all the way to CUN. By the time you clear immigration your bags will likely be ready to pick up for customs. And then you just drop them back with the recheck desk, which I believe is just outside customs clearance.

SkyTeam Elites should get priority security access at IAH.

And I'd say anything around 2 hours or so is a reasonable connection time. Less will be rushed and more will be additional padding in case of something going wrong. You should be able to book it all on a single ticket to be protected in case of delays.