Hi,
We're happy that you like the game so much!
Unfortunately you're the first one to report crashes on PC (iirc), not sure what the root cause might be, is try deleting the game and redownloading it to see if crashes stop (dw, save data is stored in '/App Data/Roaming/Godot/app_userdata/REC' not in the game folder) of that doesn't help, then we would need as much info as possible of whats happening, when, what did you do to get the effect, specs etc. (the more info, the better chance of solving the issue).
As for the commissions, up until now, dev did the art only for the game, you're actually the first individual to ask for commissions. He's open to ideas, so that's more or less a 'yes' to your question, but he'd like to give a final answer after knowing what would you like to have drawn and how much would you be willing to pay for a piece of art? Please include as many details as possible.
Cheers