If some hashtags are included in the feed source, that might not be a problem unless it repeats the same hashtags in every post. From a blog writer's standpoint, we think they use different hashtags on each post, and that’d be ok.
We do support most of the feed specs out there, as explained here. If any website including Google tools providing a native feed, we can parse and use it.
Circleboom RSS service regularly checks the feed URLs, and if there is an error at the originating URL, it suspends it for as long as 24h to give enough time to the Feed owners to fix the issue. Circleboom RSS service will automatically recheck it after 24h and will continue to post Tweets if it can get new data from your end.