- can the magic have a natural hum to it, or does that have to be an upgrade?
So no, lasers don't hum! What hums is the electronics that generally power lasers. Generally, lasers have to have a power supply that will hum or a flash lamp. Since magic, in this case, is activating the photon beam, it wouldn't make noise.
I can't really see any way that you could upgrade laser magic to have it make noise?
- can I upgrade it to be able to cut through things, given limitations?
Depending on the wavelength, frequency and duty cycle, lasers can naturally cut things, so you wouldn't even need an upgrade for it. For example, a CO2 laser can cut and etch.
If I were you, I'd do the following:
:: [Magic: Can produce a CO2 laser beam]
:: [Restrictions: Beam diameter of 1 mm; can only produce one beam at a time]
(this can burn)
:: [Upgrade: Can change change the wavelength of the laser to produce different colored beams]
@Ru