what's happening to my Aloe plant? ID of aloe?

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.

The picture is sideways.

At the bottom of the picture (left side if it gets turned around) are some leaves that are no longer thick and succulent. I would trim these off, and others like them.

I think this plant is one of the Haworthias rather than an Aloe, but I am not sure. Your care is right: Deep soak, but let it get fairly dry between waterings. Fast draining mix. Bright light but not direct sun, though maybe direct winter sun would not be so bad. Surely keep those sheer curtains in place through the summer!

That doesn't look like good soil for a succulent/cactus to me. Looks like peat.

@Diana_K, thanks for the info. Upon searching about Haworthias, it looks like it could belong in that family. @purpleinopp, the mix i bought states 'cactus-mix soil' on the bag. It seems to do the job well for my other plant, a tree aloe. Thanks to both of you for your responses.

These plants need quite a good drink of water as that is what swells out the leaves, the soil definitely looks very dry so I would fill a basin /bowl with water and sit the pot in this, allow the soil to soak up as much water until the soil changes darker, that's an indication that the soil is damp right through., then drain the water running from the pot, once the water has drained, don't water again for a few days.

When I grew those plants, I added some compost to the cactus soil otherwise the cactus soil on it's own is toooooo free draining and the roots don't get a chance to take up moisture,
Hope this helps you out a bit.
Good luck, WeeNel.

I agree with Diana_K.

WeeNel is right about how to water:
Deep soak so all the soil is thoroughly wet. This is best accomplished by plunging the whole pot into a bucket of water. Standing the pot in a deep saucer will work, but takes longer.

Then allow the pot to drain, and go drier between watering.

My Haworthias are outside (zone 9b), in a pot with regular (house plant) potting soil, and they go about a month in the summer between watering. Winter rains. They are in the shade of a tree, but it is very bright. No direct sun. I have also kept them in a higher sand content soil, a cactus sort of mix. They do seem to be a bit thirstier than most cactus. The more water retentive soil seems to suit them better. They do need to go pretty dry between watering, though. I am watering it with water removed from my aquariums for water changes. Low level of fertilizer with every watering.

Great advice Diana_K