oh ya and as far as time goes... its your call as you can change difficulty and your level at any time to effect what enemies drop and whether or not you need to spend additional time leveling (Im also a DS RPGing school commuter with a lot of dead time so I feel you on that)
Im playing The World Ends With You right now and its an awesome RPG. A nice change up from the standard style of play and story. As for the touch features they are the primary way you battle and are used in one of the funnest ways Ive seen on the DS..... sooo just my two cents