The printer should be fine for decals. The ALPS printers are thermal wax, and because the inks are wax (as opposed to resins) they should work fine on the laser decal paper. I use that in my ALPS all the time. Resin printers use a very high heat to melt the pigments and they will destroy decal paper, but wax is applied much cooler. The difference in the inkjet paper is a coating to keep the water-based inks from running, so it should work as well.
An overcoat is always needed because the wax will scrape off the decal paper. If you handle the decals carefully, then the overcoat you use on the model will suffice. I always coat mine with Micro liquid decal film.
Go to Yahoo groups and check out the alpsdecal group message threads. Just about any question you might have has been posed there!