Haven't had any problems with the touchpad. It can be a little sensitive at times but you can reset the sensitivity. I never was a fan of touch pads on MP3 players but I can see why people like them (more precise control of scrolling speed).
MTP players allow the folders on the player itself to be accessed and music drug to. You can open it up like an Explorer window and copy the files over just like that. MTP is what's in PlaysForSure devices such as the Zen Vision M.
The Player usually has two directorys.
\Media Library\
\Data\
Inside Media Library there is a folder for each content type
Music, My Playlists, My Recordings, My Slideshows, Pictures, Video, TV(the folder that XP MCE transfers recorded shows to) and ZENcast(Creative's audio/video podcast program)
You don't have to use any kind of program: if you have WMP10 or WMP11, you can just drag and drop.
It doesn't matter where you put the files(as long as they're in the correct type folder), as they usually get the track info from the ID3 tags.