In short, the HSA and Gold HRA plan cover the same items at the same percentage, the difference is how much the deductible is - ie, how much "risk" do you want to take. At our income levels and typical expenses, we can handle paying the high deductibles and essentially gamble on whether we're healthy or not. The DPMP has a higher up front cost, but the deductible is low and seems to be a better overall plan in terms of how it pays but it's expensive. As I understand, those with serious medical issues in their family and/or high prescription drug costs do well on DPMP.
The HSA plans let you save and invest health care $$ that you don't spend. The Bronze plan is cheaper, but the deductible is high. You can take those dollars you didn't pay in premiums and put in the HSA. If you don't use much medical (preventive care like check ups are covered at 100%) over the year, put the different between the premium for Bronze and Gold into the HSA and can be invested and you win. If you have lots of medical expenses, you can just either pay them out of pocket and leave the $$ in the HSA for another day (or retirement) or take them out and pay. In the end, it's about a wash for the HSA. The HSA has a lot of tax benefits for our income level.
When you report a "life event" on DeltaNet, you enter the date of the event (losing medical coverage) and the Delta health coverage starts that day. It would take a few days for it all get entered, accounts setup online, etc but it's effective right away.