Like how this turned into a basic refreshing lesson for the rules of the game. Ngl, I was a fan of Master Rule 4 and I'm kinda worried about what Master Rule 5 will do to the meta (build-a-board / break-a-board or lose), but luckily, we don't even need to think about that here, as that's clearly not what duels will be like. Huzzah to that thought. 
I can't get behind the whole pack opening thing though, as it adds a lot of random factors into it, which I really dislike. I mean, you can mitigate it by saying something like what webboysurf suggested with a base deck and a list of cards you plan to use down the line, combined with something like a shop where you can turn your cards in for some form of currency, which can be exchanged for cards later on. (Think something like dust in Hearthstone) That would make it not purely random, so people who only pull trash can still get the cards they want, just that they'll have to invest more cards / currency into them than they'd have had to by pulling them from a pack. Of course, trading can also somewhat fix this, but trading with trash is still no good.
Unique cards seem like a good way to build character, represent character development and giving the Decks some flavor. Although I'd not make it mandatory, as not having a specific ace monster to rely on can also suit some characters, if they have more of a 'united we stand' mentality (pun intended) when it comes to their cards.