Beginner Gardening: what's happening to my Aloe plant? ID of aloe?, 1 by Flixy

Flixy wrote:
A quick info about the background of this aloe plant: i received it as a gift, and the leaves were quiet green. I re-potted it in a cactus-type of soil and placed it in front of a west facing window (no shade aside from fabric blinds that filter light in sunnier weather) in the winter in Vancouver, Canada. I've only watered it every 7-10 days with minimal amount of water and let it drain out of the pot. It's never sat in the saucer with water. Gradually over the past few months, the leaves have been gradually going dark green with strange 'water-stain' marks on the leaves. It's now Mar 2013, and with increasing daylight, the leaves are getting darker green and a couple are a mix of green/brown. The leaves aren't mushy but stiffer like they are dried out. The central part of the plant seems to be sprouting new bright green leaves. Please see the picture on what i'm trying to describe here. The questions i have are:

1) are the outer leaves just dying off?
2) does my plant have root rot or some other disease?
3) are the green leaves an indicator that everything is fine and i should just pull off the dying leaves as time goes on?
4) what species of aloe do i have here?

Thanks for your responses.