May I use latex poly over oil gel stain on furniture?

Yes, you can put latex poly over oil gel but be sure the stain is fully cured.

https://woodworking.stackexchange.com/questions/2068/can-i-apply-water-based-polyurethane-over-an-oil-based-stain

HTH

I do not think you can use a latex over over the oil stain. I would not consider Latex glaze being a sealer. I would go to a paint store and double check so that you don't end up a sad mess on your hands.

Yes you can! Make sure the gel stain is cured. At least three coats should do the trick. Latex glaze is a sealer.and gives a hard finish.

I wouldn't recommend it. It can cause the paint underneath to bubble up (and yes, I speak from experience!) You will want to strip the old paint first and then lightly sand.

You can, but I agree - strip first.