You have to remember that not all services have ALS nearby. If there are no sign of rigor, pooling or others obvious signs of death as per the local protocols I worked at, you CANNOT stop. The closest hospital was 40 mins away on the best of days so was ALS. ALS then go their 20 mins to change things around before finally deciding whether or not it was it. But as far as my level of training goes, I worked it until we got at the hospital.
As for fire help, I agree that you can do without BUT why not use them if they are there? Extra hands to do compressions, vent, lift. By all means as far as I'm concerned they can go at it I have no problems with it. Sure another thread could be started about the costs of using them on calls where we could do without etc, etc. I have only worked 1 code where it was just me and my partner and even tho we managed, extra hands would have been used.