If there is a way to skip the launcher, or force game launch at a certain resolution, I couldn't find it.
There's a GFXSettings.Hitman.xml in the install folder but it isn't used to store user settings.
Savegames are found in Steam\userdata\<Steam id>\382940\remote\ but there are multiple folders. Each contains one data.save and one index.save file, with various timestamps...
Edit: this comment was in relation with an issue in the beta.
Quote:
•The config launcher only shows the 15 first (lowest) resolutions available on your system; all other resolutions are accounted for in-game.
Consequently you may have to launch the game at a lower-than-native resolution then pick the right one under Settings, Graphics... every time you play.
This is resolved in the actual game, the new launcher app lists all available resolutions properly.