Go to the directory/folder: C:/Riot Games/League of Legends/Config/
Open with your text editor: PersistedSettings.json
Search for: RollerButtonSpeed
You probably found something like:
Change the value to 1.
By holding C (or clicking on the icons on the left side of your champion portrait) you gain access to the champion stat panels. The panel on the top right includes the most relevant numbers (AD, AP, HP, etc.) One of those numbers is Life Steal. Hovering over the icons has a legend pop up identifying each icon.
The point of proxy farming is to provide a point of pressure on the map and to make it hard for your opponent to properly farm minions.
In the case of Singed in particular, he can clear entire waves pretty easily even very early in the game (level 1-3) compared to most champions, causing his lane opponents to have to try and fight the turret for last hits ...