easy, the energy needed to make a basic blade is so minimal it is not missed. or, the wand adept can work the wand with that much more efficiency, getting an effective 1/10 of an extra charge they can make a light saber with.
wand opportunist looks fun, and could quickly be broken by AOOing with a disintegrate. giving a legitimate weapon is better.
everything is better with warlock.However, I do like the Warlock idea...that is awesome.