I thought it might be my aluminum brewpot,
Nope it wont be the pot.
As a threshold question have you been reading about brewing? Maybe got your self a copy of Palmers book its free online here:
http://www.howtobrew.com/intro.html
One of the first things that come to mind is the question of yeast.
If you are not making a starter, you may be pitching too few yeast cells.
That can lead to odd flavors. If you don't want to make starters buy Wyeast PROPAGATOR yeast packages. They are little starter kits in a bag.
Switch the sanitation to Star San its cheap, easy, and no rinse.
You could also use:
1 ounce of vinegar
5 gallons of water
1 ounce Clorox (any bleach)
Its also no rinse and kills everything.
As an aside there are only about 200 organisms (besides the yeast) that can live in beer and also cause bad flavors and they don't last very long anyway because the environment is so hostile to them.
To sum up, I can't seem to shake this "home brew" taste!
It would be well if you could characterize what you mean by home brew taste.
Read this for off flavors:
http://www.howtobrew.com/section4/chapter21-2.html
http://www.homebrewzone.com/off-flavors.htm
Potential problems: I think I may have been misguided in my attempts to chill and aerate simultaneously by frothing with my immersion chiller.
I cant imagine that this would do anything at all. Maybe you are knocking crap from a stove top hood down into the brew while going through all that exercise?
Stove hood crap might make beer taste weird.
I also think I may have "over-carmelized" my extract by boiling for 60+ minutes. Perhaps my homebrew store has substandard liquid extract.
Nope. Most of my boils are 80+ it aint the boil.
You might benefit by going all grain. It only sounds complex when its described by people who make it so. And it can be as involved as you want it to be or not.
Anyway you need to identify or better describe these flavors you are talking about.
Is it cidery, skunky sulphury etc? Go to those pages I linked to and read em.