I happily downgraded a spare O3DS. But my New 3DS has everything I legally purchased and whatnot on it. I'm not going to risk that by downgrading. I'll just stick with the O3DS for GBA games (Since AGB_FIRM is available, I may as well.)
Most of those you list are either third party (lol Square-Enix for the FF and Dragon Quest/Warrior games and Konami being helpful in any capacity. Wario Blast was a Bomberman game. Guess who owns Hudson-Soft? Konami.), require external hardware (Kirby Tilt 'N' Tumble. And Nintendo and HAL won't...
There was a very hot girl named Mica who kind of hit on me in the uni, but I didn't follow through because she was too young and I already had a "don't date girls younger than 20 /21" at the time.