1) I redeemed a San Francisco 49ers team card back-in-the-day & received multiple copies of each rookie. As I recall, there could be three or four versions of each card - gold (colored) foil, silver (holo/rainbow) foil, gold (real 24kt) foil & the thick cardstock "Gold Ingot". I think the team card I sent in was the Gold Ingot version, which is why I may have received the 24kt versions of the RCs
The 24kt cards are not currently listed, but you can tell them apart from the standard gold-colored foil by their obvious luster & smoother foil appearance.
Unfortunately, those cards are long-since sold or traded away, so I can't visually verify them.
2) I do see that the one Redskins RC pictured also has the "99" CE logo, so maybe some rookies were printed later & got the more recent year's foil stamp.