Yes you can have dairy on Phase 1 - follow the types and serving sizes outlined in the food list.
I don't think the amount of breadcrumbs in the meatballs is going to have any net effect.
I googled El paso taco seasoning, and no, it's not SBD friendly.. You want to stay away from Malodextrin, Corn Starch, MSG and partially hydrogenated anything. And 2 Teaspoons dry packs over 20 % of the daily sodium guideline..Maybe try making your own.. (I do, but I never measure anything, so I won't post it) I use Chili, onion,garlic powders,paprika ,splenda, salt, a pinch of cayenne.
Ask the waiter what is in the smashed cauliflower. I checked their website and they aren't listed--they do list the cals/fat/carbs/fiber content.... Sometimes waiters get confused between Atkins and SB.. If in doubt, maybe ask for just steamed cauliflower, and a pat of butter, and mash it yourself.
hope this helps