2nd level would be a little low to reveal all powers. Maybe 4th level, but with the 8h casting time (no way around this, I suppose) and more costly (200-500 gp).
Analyze Dweomer would still be obsolete, then!
I'd probably make a 3rd level Improved Identify, which works exactly like Identify, except that it allows to identify one random ability instead of the lowest power one, if used on a single item only (when multiple items are identified, it only reveals the lowest power ability as normal), and gives a chance to find the number of abilities (or at least that there are other abilities) with some kind of check, maybe an opposed caster level check or something like that.
Bye
Thanee