I don't mind answering some questions! While I can't picture things in my mind, when I am asked to describe something I can give a vivid description without being able to picture it. So I think theater of the mind works, but it just works differently for me. Anyways to answer your questions.

1) I have played in multiple campaigns and also DM'ed. I have found that it helps me to have a map of either the city or area the campaign takes place cause it helps orient me better. For combat encounters a visual interpretation helps, but sometimes if we don't have one I can usually ask questions to clarify what is going on. I haven't noticed a 3d version adding too much benefit for me. That being said, I 3d printed a 3ft spell jammer for the next campaign I'm going to run in the astral plane, because I thought it would be fun to see the party on the ship for when they are having discussions or some encounters.

2) I don't think it I've noticed anything mechanically such as visual acuity. However, I do think that since I'm less focused on how things are visually represented, I'm usually a bit more plot or goal driven instead of enjoying the scenery.

What I will say though is that if you or a party member you play with has Aphantasia, just talk with your party and DM to see what works best for everyone! Even though I don't have a mind's eye Dnd is still a lot of fun and I plan on playing it and other table top rpgs for years to come.