So, if my wife employer didn't offer health insurance, then we could get it, right?

I entered in some information on that Kaiser site and wow...out of pocket expenses are not cheap!
"Your out-of-pocket maximum for a Silver plan (not including the premium) can be no more than $12,700. "

Ouch! Ours just went up to $2500, so not sure how this is more affordable?

I don't know what premium we are paying right now, since they just changed it, but under the ACA, we would pay:
"Amount you pay for the premium:$4,112 per year"
after the tax credit.

I'll have to find out what we pay per year.

I wonder how the premiums would work if I had to claim my UI too in that?

ER visits are supposed to be limited to certain things, which is totally understandable, otherwise, you would get denied coverage and you have to pay.
Currently a person with limited means can go down to the ER for a cold or to seek drugs and never pay a dime. And if you don't think people go to the hospital to get drugs, then talk to a medical professional like a nurse who works on the floor.

How will this change things? What happens if the ACA runs out of pool money? Will rates be raised then?

I mean, that's how health care really got out of control before ACA...people go to hospital/ER for really minor stuff and never pay for it. Or they fake neck/back pain and get a free ride to the ER via ambulance and never pay. Talk about expensive! All that lost money plus other factors and we ended up in a mess.

Can someone please explain how this will be avoided with the ACA?

That's what's really scary for me.

and to add to that:
My wife met with her boss who informed her that in Kentucky, 40 hospitals will be closing in the outer areas. (rural parts of KY)
Baptist East Hospitals just gave all their LPN's 2 week notices.
Norton's Hospitals are trying not to lay anyone off yet.