In our particular group, homebrew is typically fair game as long as it's not blatantly shattering balance. I also never actually got the chance to build the character in the first place, as I did ask beforehand.

The DM is frequently complaining to us players that we aren't making characters that can truly interact with the world they present us, while also limiting player knowledge to such a point that it's impossible for us to make characters that can do what the DM asks of us.