2003 Forester problems

I purchased a 2003 Forester last year about this time from my previous dealer who has a small used car business. I later ran a CarFax and found the car had been in a front end accident two months before I bought it and was never told. I noticed a couple things - driver window squeals when it goes up and down, it obviously has been painted in spots, the driver headlight was way out of wack as far as alignment, inner tire well cover damaged - small things... but now the ABS light just came on. I live in a snowy area and have not been happy with the way the Forester has been handling ... braking and it's almost like the AWD is not working properly. It has 57,000 miles. Are brakes gone? Do I chalk all this up to the accident and take action because I wasn't informed (he said he bought it from auction and they didn't tell him).

Need help....