I am thinking about buying a larger amount of Parmesan and freeze it for later use. Is this possible? How long can I keep it for? How is the taste/texture affected?
Yes, you can freeze parmesan cheese. Even without freezing, Parmesan is very durable since the low water and high salt content prevents mould from growing. The younger varieties may be more prone to mould growth (having a higher water content), but I've kept ripe Parmesan (30-36 months) for at least a year in the fridge without problems (and it would probably have stayed good much longer). Just remember to keep it wrapped in paper, not in a sealed plastic container to prevent a buildup of condensation.
I'm not going to add much as Tor-Einar Jarnbjo's answer was very thorough but just to note that you can also freeze parmesan rinds to add to soups and stews for an easy umami boost.
There is absolutely no need to freeze it. Keep it dry and cool and everything will be just fine.
I make artisan cheeses...cool and dry is how it is aged and is all it requires.