Starting out is such an annoying grind since there's so many things that you can work on. I'd pretty much suggest you keep doing what you're doing. Play some songs, get comfortable with the guitar from fretting and shift. Being able to move up and down the neck and between strings with ease is really your main goal. I'd say don't worry too much about alt picking for now but it's not a bad idea to try and get in the habit of throwing it in there. Single string stuff is great but eventually when you're going to actually want to play songs.. and while lead stuff is fun, it's all about rhythm guitar. Chords can be a super bitch to learn, even the easy ones because even if you have a simple 3 finger power chord down, you have to hit that next chord on time. Chord transitions took me hours and hours to get down quick and I still struggle with some (damn you Dm!). Picking up your guitar and fucking around with it outside of Rocksmith will only help as well but getting the basics down is really the key. I know it's tempting to move quick and start trying to learn major and minor chords but it's better to do what you're doing before getting overwhelmed. I hate to say it but your going to hit a bunch of brick walls... hell, I thought I would never be able to play Barre Chords and now they're like second nature to me. Also, start trying to memorize chord names... it comes in handy when you're playing with friends so you don't sound like an idiot as I have on many occasions. Keep plugging along... also, learning how to restring your guitar (if you haven't already) is vital and will save you a ton of money in the long run.
If you're looking to tackle chords in the future... besides the 2 and 3 finger power chords (just play a bunch of blink-182 songs)... I'd suggest start out with the easier ones first and learning to move quickly between them. So, A Am E and Em would be the easiest IMO. Then more importantly tackling C D and G... eventually moving on to F (and other barre chords) and B and Dm. Then suffering through all the weird chord shapes and stretchy stuff which I currently suck at...
As for a $500 guitar mentioned... I don't really know what to suggest. Maybe check out a local guitar shop and see what they say and get your hands on a few and see what feels and sounds more to your liking. Unless they already picked something out. I don't really frequent the guitar OT... I really should.
edit: Also, out of curiosity from everyone here... Do you guys play a rock G major or a cowboy G major? (rock being fingers on B and low E on 3rd fret and cowboy is just a finger on low E on 3rd)