I'll take one, sometimes two in certain situations with a non-critical patient. Critical patient I'll take one rider.
They generally ride up front, in a forward facing seat, seatbelted in. They don't get in the cab until my partner is ready to hop up front and drive unless it's someone who I'm not worried about rifling through my stuff (read: elderly or "high class" for lack of a better term). Seems to be the opposite with most here. The cab of the ambulance is the safest place for them to be. A side facing bench seat is not a great place for anyone, but when it comes down to it, I'm covered by insurance from work and also am used to being in the back of the ambulance, family and friends are not. In select circumstances, listed below, I'll allow a rider in the back but if we're going code 3 to the hospital riding in the back with me and the patient isn't even an option.
Only time they're in the back is if I think it will benefit the patient or help me such as a pediatric patient, translation, calming, things of that nature that have already been covered.
I'm not a huge fan of having people in the back with me, especially with a sick patient. 1) they get in the way. 2) they can be very distracting and interfere. 3) it's not safe. If we are returning emergent I'll take one rider and they ride up front, not in back. I can still communicate with them to let them know what's going on and gather further information
With that said, it's my office, my rules. If you're being an :censored::censored::censored::censored::censored::censored::censored: then no, you cannot ride with me. I've pulled over a few times and booted an unruly family member out of the ambulance, in a safe place obviously but it's definitely happened.
I'll generally try to talk someone down on scene or have my partner do it if they're hyped up, if they can't calm down they can't ride. If they're being rude, sorry charlie, you're not coming. If they're an emotional disaster, well...that's a case by case basis. Do I want them trying to drive a car to the hospital in the state they are in? Do I want to be "that medic" who wouldn't let the husband ride because he was extremely emotional after we get ROSC on his wife and he wrecks his car on the way to the hospital?