Should I repeat the prayer if I suspect that an action during it rendered it invalid, even if this occurs before its time expires, or should I wait to consult scholars, even if its time then expires?

If you doubt whether an action you performed during prayer invalidates it or not, the default is that your prayer is valid, and you do not need to repeat it, because every doubt is disregarded until its validity is proven. Then, ask scholars about the ruling on what you did. If it becomes clear that it invalidates the prayer, then you must repeat it; otherwise, you do not.