I live outside of Philly (22 years now). Originally from Dallas (first 36 years). Been to about 4 Cowboys/Eagles games in that time. My observations:
o Veteran's Stadium was much worse than the Linc
o Watch your six going and coming to and from the stadium
o 200 section and lower - people are pretty cool (high priced tickets and most folks from the burbs)
o Don't incite, don't be overly demonstrative - especially if the Cowboys are winning or win
o Expect to get wet and yelled at, but don't respond
o Stay in your seat during the entire game
o If possible, don't wear anything Cowboys
Actually, believe it or not, most Eagle fans are pretty good folks. Particularly folks from the suburbs. It's those South Philly low life's that grew up in Rocky's backyard ya have to look out for....