Basically, just about any ship that wants to travel any distance has to be capable of Warp Travel. Since Battle Barges are brought in for battles and crusades all over the various sectors, they need to be able to warp.
As for description, I don't know of any barge-specific warp travel, but Inquisitor by Ian Watson describes small ships and a Black Ship (the psyker-filled ones), Dan Abnett's Eisenhorn books mention various large ships in warp (since the Inqusitor's small ship is usually abord some larger cargo ship or other trader vessel for warp travel). Generally, just just revolves around a swirling sea of immaterium. Only the Astropath can see the currents that they travel on, but there's a general swirlyness anyway.
All chapters will work together, although some aren't very comfortable with it. Space Wolves and Dark Angels have a grudge, for one, and I'm sure others do. If the Imperium orders them in, though, they're Marines and so they're always going to fight, just possibly not be greatly friendly and/or cooperative with the other chapter (think "we're going to show we're better than you and do it ourselves" for the SW/DA grudge)
Space Marines can live quite a long while. The studs on their heads are 100 years service, and I know of some models and pictures with at least three studs. I'm fairly sure that some of the oldest veterans reach 500, but I couldn't give you a source for that and I don't have the Space Marine Codex in case it mentions in there.
Hope that helps