Have a look at OWL (OpenStreetMap Watch List): http://wiki.openstreetmap.org/wiki/OWL_%28OpenStreetMap_Watch_List%29
It only shows changes in a particular area. Though it seems OWL is currently down, I don’t know when it will be working again.

For your second method, see http://positron96.appspot.com/osmfilter.html
I’ve not tried it myself yet, it should exclude any large changesets from the RSS feed.

There have been suggestions of adding something like these to the main history tab on openstreetmap.org, though I don’t know if there is any progress with that.