Well, I guess cases like that are very rare, but you have a point.
As for DLCs or downloadable games, it depends. If I didn't like very much the game, or I know I'm not gonna play it for a very long time (or never again), I delete it even if it came with free DLC. I tend to not buy DLCs at all.
Yep. I generally prefer buying physical. I choose the downloadable version only if the price is very advantageous.