Does anyone know how beneficial using Candlelight is to level Alteration? Thanks!

I don't think it's very effective. You're better off casting 'skin' spells in battle, detect life in big cities, detect dead around large groups of dead bodies, or telekinesis.

I don't even think it's possible if so, it will take a very, very long time.

I found that the best way to level Alteration is to spam the use of Detect Life in a populated city. For example, Whiterun during peak times. Equip enchanted gear to minimize/nullify the magicka cost.

I think it is possible (pretty sure I had a level up once after casting a candlelight spell), but as Vaen says it takes a veeery long time.

I don't use much magic, but given the low cost of using that spell I thought.....'hmmm, why not?'

It's definitely possible. The problem is you only get 2.5 skill XP every cast, according to the wiki. For comparison, Magelight gives you 12 and Oakflesh gives you 103. Detect Life is 6.5 per second per target and Telekinesis is 170 per second.

That means if you're using Candlelight to level alteration, be prepared to sit around casting it hundreds or even thousands of times between each level up.

I've found that casting water breathing while standing knee-deep in water levels Alteration pretty quickly. If you really want to cheat, then enchant your clothing, hat, ring & necklace to Fortify Alteration 25% each, then the magic cost for telekinesis is 0; so you can go outside, cast telekinesis on something, and fast travel to a far location while you are still holding the item in mid-air. You will probably be at 100 in Alteration by the time you get to your destination.

Lacking those adept-level spells, you can level Alteration by casting Oakflesh (or better) in a combat situation; you can cast it several times during the same situation. I like to go to the draugr ruin just north of the Mages College to train my combat skills. It respawns.

In my experience, the combo of flesh spells in battle, with detect life in cities and a little fun with telekinesis can easily get you to 100. Candle and magelight are not going to make a difference.

I usually stand in the middle of riften market place casting detect life in one hand and using telekinesis in the other to hold up a cabbage or basket or whatever. Obviously with 100% reduction stuff equipped.

I do wish telekinesis would be a bit more like it is in bioshock and could do some real damage, like using it to pick up a sword off a table and throwing it at someone.

That is an excellent idea. It never occurred to me to dual cast when power leveling.