I know that the retail version contains an exclusive chase level, some cell cards

But is there also a 2nd exclusive level ? I saw something about foil cards AND foil puzzle cards. Are these in the hobby boxes, too ?

The Foil (silver, bronze, and gold) sets and the foil puzzle cards are available in the hobby version.

The backs of the sketch cards are different for the retail vs hobby.

While in my local Target today we purchased two packs of SW Gal. 6 {$2.99 ea.} just for the heck of it. We pulled one special card from each. One was a Foil Bronze Parallel Card of Greedo #4/10, by Brian Rood. And the second one was a Cell Card of Vader & Leia #3/9.
Stupid question...what are those blank white cards in some packs with the little square glued to one side, a protector of some type ? I've gotten about 3 so far in this series and Rise of the Bounty Hunters packs.

Something to try to confuse pack searchers perhaps? Just guessing, don't buy these.

I think they are security tags, if they don't get scanned they set off an alarm when you leave the store.

a security device sounds correct.