Plastic polarizers will loose their polarizing ability when exposed to heat so that can definitely be done with a laser (wavelength unknown, maybe IR-laser works best). I'm not sure what kind of properties a heatexposed "damaged" polarizer will have (if it interferes with polarization or not). For a micropolarizing layer you will need two stacked polarizersheets if you aim for polarizers. In worst case one polarizer could jam the function of the other one. I have no clue without testing this first (have polarizers, maybe even still have a couple of partly damaged ones).
While plastic polarizers by time fries in front of projectors, retarders seems to be a lot more durable. Probably because they're much more transparent and doesn't absorb any energy. I haven't noticed any signs that retarders change their properties when exposed to projectorlight.
My guess about retarders and heat: If the properties of a retarder can be changed by a laser i doubt they can be changed in a controlled manor from horisontal to vertical alignment. The result will probably in best case be something that will be entirely transparent without the retarder property or something that messes up polarization badly. As said the last sentence are only guesses and assumptions from my side.
So, the field is somewhat open!
Curious: Do you know how these u-pol films for passive 3dtv's are manufactured? The process?
Mb: Asus P5W DH Deluxe
Cpu: C2D E6600
Gb: Nvidia 7900GT + 8800GTX
3D:100" passive projector polarized setup + 22" IZ3D