A wand is like any other tool that channels energy through it to come to some end result projected through it. guns, air hammers, elctric drills, etc.. all share a commonality in that ther eis a chance for them to go awry. misfire, not fire at all, backfire even.
Depending on the nature and quality of the item, those chances are raised or lowered, but are sill present in some way.
I treat wands, rods and staves the same way. These are a magic users (and sometimes other PC's) "power tools". Having just one of them can be a total game changer. It can allow a PC that normally wouldn't stand a chance against a monster to be able to defeat it rather handily.
but, in my world, wands, rods and staves are wielded very carefully because the possessor knows or finds out soon enough sometimes that even wands have a chance to not fire or backfire and cause damage to themselves.
This makes wielding that wand of fireballs a bit of a sticky thing. yes, the damage it can do to an opponent is great (6d6 to everything in it's area of effect) but, the very idea that the wielder has a chance for it to blow up in his/her hand causing that same damage to themself and any of their teammates nearby, well, that makes them think harder about if the situation is dire enough to call for it's employment.
Also, the chance for it to misfire, meaning not fire at all on that attempt, could seriously hose a plan of attack. Sure, it could be the saving grace of the mission, or it could make it's wielder and the party come out looking like bumbling fools.
I think MU's and other magic using classes need to have wands, rods, staves, rings, etc... available to them, even at lower levels.
As soon as they reach levels enabling to make those items, I allow for it, BUT the lowest level able to make them leaves the items with the highest risks. Each level gained above that minimum level reduces the risk of backfire or misfire to a certain minimum.
Of course, they don't have to make the items themselves all the time. I make these common enough that they can be purchased in most higher end magick shoppes. Again, with the risk for each item at various levels of risk as determined by a percentage dice roll.
Magic is powerful, but it is dangerous as well.