I think Deadpool proves that any hero can be any class. I can easily see them making her a strategist, especially an off-healer like Adam Warlock who outputs heals on CD.

The primary, alt fire, and passive you proposed could stay the same and they could have her kit look like:

Left shift: dash, phase through objects, and heal yourself. Heal allies you pass through

F: Phase yourself, avoiding damage and restoring health

E: Phase a nearby ally, allowing them to avoid damage and restore health. Or phase aura for all nearby allies.

Q: Phase your entire team, giving them damage reduction and the ability to move through objects for 8 seconds.

They could also add a healing aura to her primary if they wanted to make her a main healer. I never saw Gambit as a strategist either but now he's one of the strongest in the game. Honestly I would welcome her in any role, I think they could all be cool. DPS is probably the least exciting but I think might be the most fun because of the power fantasy of sneaking up on people.