Everyone should use the same commands.
As for the play, that is what guys like to do. We have 3 members in our family and our dog plays and interacts differently to each of us. Yes my husband is rougher with our dog, but she enjoys this. My daughter is more playful like a littermate and does more fun things, and I am the consistent one like you. I think its fine that you both have different roles, but the commands and hand signals should be the same.
You may want to experiment in using different tones in your voice, a male voice is often more commanding. Be confident with yourself and your commands, it may take a little time. See if you can find some obedience training classes where the instructor is open to both of you training on the field. Someone objective like a trainer can point out things that may be hindering the dog's responsiveness to you.