AMAR Duel mode (All Masteries All Runes, 1v1 or 2v2, 5-10 minute matches)

An idea that came to mind the other day,. Obviously this would be entirely up for debate and change, but I think League could really use a very short, more "arcadey" style of game mode for quick rounds of random mayhem. The rules:

Cut-Down version of the ARAM map, only to half-way between the first and second tier towers on each side. All masteries, Keystones and Tier 3 runes equipped on every champion, starting level 3 with a rapid over-time experience gain, and minion experience doubled. Gear is a free pair of any boots, and 4000 gold to buy any equipment you choose, no backing and no shopping. Summoners have 75% cooldown reduction. Which ever team scores a kill or tower death first wins. Maybe even an "Out of Three" point system, since the matches could be very short with every rune equipped at the same time. Some champions would likely be very abusable, so maybe some fine tweaking could be helpful for balancing purposes.

Just a random idea I had the other day, feel free to comment or add!