zukiphile, thanks for the satire. You played that one nice and dry; I like it.
JimDandy, first, your plan assumes the citizen has the financial means to challenge the ruling in the first place, since your plan assumes compensation after the win. I don't know about you, but I find initial lawyer's fees and court costs to be a consideration whenever I am tempted to challenge anything or sue anybody, and I live fairly comfortably.
For somebody on the lower side of average on the economic scale, your plan would not work at all, as they would very likely not have the means to file a challenge in the first place.
Second, your assumption is that the incurred delay of the right, and necessity to challenge the ruling, is no big deal. To some of us, it is a very big deal.
Quite frankly, if you wanted to propose having the government set up an OPTIONAL system, that would allow private sellers to conduct NICS checks if they wished, and that would confer indemnity against future lawsuits if a buyer who passed the check went on to do a horrible thing with the firearm, I would not have a problem with that.
It would accomplish what you desire, which is to enable private sellers to check prospective buyers if they were at all unsure, while it would not require participation. There would be a carrot (indemnity) but no stick. That would be ok with me, or it might depending on cost of establishing and operating the system.
That is not what has been proposed. I do not, can not, and will not support such a mandatory system; nor can I countenance ceding so much power to the feds.
EDIT: It has been pointed out to me, and I had been thinking about this too, that such a plan could also be bad. As things currently stand, we are NOT generally liable for the actions others take with things they buy from us. For instance, if a man buys my truck, and then wrecks into a school bus, that should not come back on me.
Having the system "indemnify" sellers would imply that they otherwise should bear a liability that they don't bear. So, I don't like the indemnity bit on second thought, but would still be ok with an OPTIONAL system, if costs were supportable.