As Krensky said, those are common house rules. EDIT: One nuance that some people go for is to make the penalty / check less harsh for one-handed crossbows and firearms than for other options.
Also, speaking from experience, when I played a bow/ fire lance user, I'd always set up a shot first if I had them out in melee. Most commonly by first tripping an adjacent opponent before shooting them, or at least taking a 5' step back. If you wanted to encourage such play, you could have penalties / concentration checks only apply if you're next to an opponent who's not flat-footed.