So I cast an ad nauseum. Is there any point that I could cast surgical extraction to remove all other ad naseums from my deck so I don't end up drawing them from ad naseum's effect?
Not really. If there is an Ad Nauseum in your GY prior to casting you could do it, but the Ad Nauseum you cast is placed in the GY upon resolution of the spell. Well after you have drawn all the cards.
Nope. Revealing cards is part of the spell resolving. The Ad Nauseam you cast being put into your graveyard is the last step of it resolving, so you won't be able to target it with Extraction until after all your card drawing is done.
you cant cast spells during the ad nauseum flip. and adnaus doesnt hit the yard until its done resolving (you finish flipping). I believe you can surgical extract in response if you already have an ad naus in the yard
Ad naseum question