Mates, mates, don't worry.
Ofcourse, the Feyenoord-fans have some scum amongst them, but every firm does have. Few years back (last year?) they've been warned by the UEFA after the firework-incident vs. Lissabon, they're watched sharply, believe me. Dutch fans can only get tickets if they have a club-card, and the latest expectation is that there will be around 25.000/30.000 people. Last home match, vs. Sofia, the Feyenoord-fans were absolutely splendid. They sung throughout the whole match (which was extremely dissapointing, 0-0) and just were fantastic. There are TIFO (banners, flags, fireworks) planned for this thursday, so it will be a very good atmosphere. Besides that, you guys go into the stadium using the railway-station, which will be protected by loads of police, so don't worry. After the match, just calmly leave Rotterdam and nothing will happen. If you don't search, you won't find trouble. 2500 english, 25000 dutch - why can't that be the guarantee for a fantastic night? Respect from both sides (of fans), that's what it is about. And I don't think Rotterdam will see this as a Holland vs. England clash, they know Blackburn don't have a hooligan reputation at all.
About the match...well, Feyenoord are getting back on track and my scouting has learned me that especially Hofs (pass and shooting style of player), Greene (pacey and good defender) and Huysegems (who's a very dangerous winger, if he's in a good form...which isn't always the case!) are good players. They've got a decent goalie in Timmer, there defence lacks a bit of quality, so McCarthy and Nonda(?) will have chances, for sure. Their midfield is their strongest part, but if De Guzman is injured, that's a good thing for Rovers. He's another very, very talented player, who is able to turn a match around with his passing and dribbling. Especially at home Feyenoord are very strong and play like Rovers (at home) - with loads of passion and tackles flying all over. Will be an exciting encouter, I'm not sure about the result but 2-2 is fair.
To all, have pleasure, behave, and enjoy the fantastic atmosphere at one of worlds greatest football-temples!