I've been a MM user (lifetime license) for a number of years now and can vouch for it's ability to do 2, 3 and 4 (not sure about 1). The mp3 tagging support is superb and the mp3 conversion uses the LAME encoder, so is excellent quality.
Would I buy it now? Not sure - there are many more efficient players around for free (e.g. foobar, xmplayer etc.). Tagging can be done via Picard http://musicbrainz.org/
- although the track properties in MM gives you a huge amount of control over the tracks (e.g. tempo, mood etc.) - and there are a thousand-and-one CD rippers, converters and burners.
The MM skins really put me off at first, but the non-skinned version looks better.
So, it's good, but you'll really need to demo it before buying to decide if it's $40 better than the free stuff.