Screen brightness and device lock

[Cirovg]

Hi all,

I'm a new Nexus 4 user, sorry if this has been covered before, I can't seem to find any info on this.

1) Is it possible to set the screen brightness to reduce automatically after, say, two minutes of inactivity without the device actually going into sleep mode?
2) Is it possible to lock the device just by touching the screen? I don't like having to press the power button every time.