yes it will be fine with slugs i suggest the Foster (rifled) slugs for best accuracy the sabot slugs are made to be shot in rifled barrels and do not shoot accurately in smoothbore barrels

Hi Steve and welcome. Yes you can. Foster Type Rifled Slugs are recommended for best accuracy results from the fixed cylinder bore. Example: budsgunshop.com/product_info.php/products_id/66055/remington+12+ga.+2+3+4+1+oz+lead+slug

Yes.

Hi Steve, this has a fixed cylinder bore so shooting slugs will not be an issue. Use rifled slugs for best results.
Stay safe & have a great day!