1. Why would switching jobs cause a problem? I've changed jobs several times over the past few years and never had a moment's trouble with health insurance.
2. Pre-existing condition are covered if you had insurance from another carrier in the past 63 days. If you wait past 63 days, then you have no one to blame but yourself.
3. I was a small employer for 12 years and never had any trouble getting and paying reasonable premiums. One of my employees had numerous conditions that required expensive prescriptions and doctor's visits.
4. I've never heard of anyone losing their insurance due to an illness. If you can't pay your premium because your sick, well that's a different matter. You can't expect them to keep covering you if you don't pay the premiums.
P.S. Under this health bill, you will no longer be able to have your health savings account.