Whenever the rss feed is edited in the source, it does so in the list of recent posts. Is there any way to avoid this?
We use it to import news. It would really be more useful if once the feed is imported we could edit it to give some formatting to the text (or change the user, the post title…) without losing all the changes every time the feed is re-requested.
Today a RSS source updated old content and now is in top of my latest feed. Is possible to avoid this to happen?
When my feeds are updated I like to know it, so the behavior you describe works as expected for me.
What would be the alternative? Do you only want to know about the initial published content? 
The problem I find is that there are feeds that for some reason update every x minutes (I have even had a post with more than 100 modifications).
I know that the problem is the source feed, but I was just asking if there is a possibility that the post that includes the feed is updated but not listed at the top.