You didn't hear it from me
Using proxies in casual, everyday Magic is fine
Q: Will this case safely stack with other boxes
Once you've sufficiently buffed your minions, defeating your opponent is as simple as playing the Aggressive Mammoth, which will give all your characters Trample and prevent the full force of their might from being blocked by your opponent's creatures
Lets get to it, starting with one of the most degenerate sets of all time: Urzas Saga Significant cards on the list: Argothian Wurm $3 Gaeas Cradle $70 Gilded Drake $30 Karn, Silver Golem $4 Lifeline $4 Lightning Dragon $3 Morphling $10 Serras Sanctum $20 Tolarian Academy $25 Temporal Aperture $2 Time Spiral $25 Yawgmoths Will $15 Of these, only three can fairly be called tournament staples: Gilded Drake, Serras Sanctum, and Time Spiral
And, being able to have up to four copies of the same card means you can pick your favorite songs and ensure Ursula is getting her time in the spotlight