Nobody works in EMS as part of a get rich scheme, but making enough to be able to participate in the lifestyle you desire outside of work is certainly of value. EMS workers in countries like Canada, Australia, and New Zealand are afforded a different level of pay/respect than that received by most US providers. As much as pay and respect can't be primary motivators, those two things have a powerful effect on career longevity.
If you choose EMS as a career the most disastrously unhealthy thing you can do is allow it to become your everything. Your non-EMS friends become a lifeline to the outside world. Don't let them go. Whatever your other passions are maintain them.
As for helping ourselves, frankly we're lousy at it as a group and certain risk factors will never be avoidable. Night shifts will always exist, paramedics will always be placed in stressful situations, and schedules will always make healthy diet/exercise habits difficult (but not impossible).