Heya. I recently made a 5-color Ally deck too. It's a little more combo than this one, but I definitely like the focus on combat this deck has. Allies can get ridiculously swull out of nowhere and take the game by surprise. I'm stealing your idea of using Stunt Double and Taurean Mauler for my deck, so feel free to make those suggestions on mine if you want the suggestion count. (:

As far as suggestions for you, you've already got a lot of them in your Maybeboard. I would give Eerie Interlude a big thumbs up - it's great for evasion or triggering a bunch of ETB abilities simultaneously.

Also, Unified Front is cheap and always awesome to draw into. I usually tutor for Kazuul Warlord if I draw Unified Front - the combination of the two gives me a 7/7 and four 5/5's, plus 4 +1/+1 counters to the rest of the board.

One idea I don't see on your list is Mirror of the Forebears. It's great for the flexibility that comes with it - one turn it can be a Murasa Pyromancer, the next a Hagra Diabolist. Also gives you an edge of protection against boardwipes, since it's not always a creature.

One more recommendation - I find running War's Toll gives a creature-heavy deck like this advantages against both control and aggro. People generally won't want to swing into you, encouraging them to attack other people if they decide to swing all out. It also keeps UW control from tapping lands for mana on their turn and yours, forcing them to play more conservatively.

Okay I lied, one more. Consider Odric, Master Tactician. I shouldn't really need to explain why he'd be a great fit for this deck's style, he speaks for himself.

Good luck! I look forward to hearing how this deck fares.