No robber on first round
I would like to suggest that on the first round players shouldn't be able to rob others. It's so unfair! It seriously messes up the development of the game and player's strategies.
There's already the friendly robber option IIRC. Friendly robber does not allow you to place the robber on a hex with a player who only has 2 points. When you open the custom game you can select it. It will make starting a game much slower due to the negative impact of matchmaker though.
On the other hand, the default games should NOT use house rules. If you want to play with some custom rules, the current matchmaker is a horrible solution as I have already said in a lot of different topics. No way to implement any solutions offered by the players.