Yes, there are a lot of fear-mongers scaring folks from using milk or cream in icing. Sugar is a preservative as is salt, so if you use salted butter, you have double action as preservatives. The only issue you might have, is as a commercial baker, where the food safety rules are a lot tougher, mainly due to the fact that they have to cover a lot of possible hazards or risks. Mainly due to the fact that the temperature in a commercial kitchen can be extremely high and the heat is an issue when using dairy products or eggs. In fact, the standard for egg use in commercial bakeries, is 20 minutes maximum at room temperature and then dispose of them. That time frame is likely less than the time it takes most folks to get the eggs through the checkout line and home from the supermarket.
I know on the Wilton site, there are and have been a lot of folks scaring people about using dairy products in their icing. I know this because I took it upon myself to dispute these claims and educate some of these folks and it has on a few occasions, annoyed a few folks. BUt the truth is, that Wilton gives the same time-frame for both kinds of icings on cakes to be stored at room temperature, 2-3 days all shortening and water or butter, shortening and milk and cream. Now generally, I find that the timeframe is much longer.
Anyway, Dawn, it is nice to see that you are on the same bandwagon, haha! Hhmn, I may have to recruit you onto the Wilton site the next time this issue comes up. I need support, haha!
Hugs Squirrelly Cakes