The "draw a card" part doesn't feel red. I know that when you're not discarding an artifact, it's just looting but it doesn't read that way. It reads like he's casting this...

Gambling
Instant
Flip two coins. For each heads, draw a card. For each tails, ~ deals 2 damage to target opponent.

Does that really feel red? I mean it's potentially a divination in red and red isnt suppose to get that kind of card advantage. At worst it's a better Lava Spike. Every turn.

What if discarding an artifact just let you reflip? That way it would basically be red looting, but give you some control over which option you get (because sometimes you really want that 2 damage over a card).

Also, this is somewhat off-topic, but I'd really like to see the flavor text as: "Heads I win; tails you lose."

I agree on that flavor text change.

I personally really like this card. I can see how the card draw might seem a bit out of color, but personally I think the circumstances required make it less egregious. I mean, you have to untap with this guy, pitch an artifact, and then win two coin flips just to net a 1 card advantage from him. I don't perceive him in the same way you do because I don't see spellslingers as casting spells like spellshapers.

As for the reflip idea, I feel that takes a potentially exciting and powerful card and makes it kinda meh. It would feel like an uncommon to me at that point.

I think it would still be a bit too complex for an uncommon at that point. I really don't have a problem with this card, colorpiewise (it's a word). I may be a little worried about power level, but that's really an issue that playtesting will either confirm or disprove. In either incarnation (double flipping or reflipping) I like this card.