Yes, your out of pocket is premium + out of pocket maximum.
No, HSAs no longer have caps (at least policies signed after a certain date, or in some states; I think pretty soon they'll have no annual or lifetime maximums at all); they're essentially "you're at risk based on your deductible for non-preventive services up to the out of pocket maximum, but excellent essentially-free care for the rest of the year once you hit that cap"). (there are some weird edge cases, like Rx drugs outside the hospital, potentially non-covered services, etc., but essentially a $500k hospital bill for some serious trauma would all be covered after you've paid the $5-7k out of pocket maximum (probably met on the way to the hospital or within seconds of entering the ER, if it's a serious trauma)
You can solve the "poor have no use for tax deductions" by giving them the out of pocket maximum into the HSA; it's free money in a personal allocated account. Or by making some deductions refundable or credits (similar to the EIC, which is most of why Puerto Rico wants to become a state now...most citizens would earn a federal tax rebate!)
The quick fix is probably to make personal purchases of health insurance also deductible, rather than removing employer health insurance deductibility. And push people into HSAs, with some people getting HSA account filling by the government. No one should be against this (except I guess "any tax decreases are bad, since we're already operating at a deficit")