zune questions what features are and things

I don't have a Zune but I feel that I know enough to give you some answers. I have 2 video playing iPods (5.5 Gen and Touch) and 1 video playing Sony.

Yes, the Zune plays movies - all you need are the headphones to listen to the audio. iPods (Classic, Nano, Touch, and iPhone) are the same way. You do not need a dock. The Zune Marketplace store doesn't have the video variety that iTunes has. I think it has music videos for sale and video podcasts (which are free). Where do you get movies that will work on the Zune? That is the million dollar question. If the movie download has any sort of DRM (Digital Rights Management - the short story of this is that it is copy protection that limits what you can do with it and is found on some downloaded music and almost all commerical movies) chances are it will not play on the Zune. Unless it comes from the Zune Marketplace. Some people rip DVDs that they own. Technically, that is illegal in the United States because doing so will break the copy protection that is on the DVDs. The breaking the copy protection is the illegal part. Copying isn't so much, but you then can't distribute (ie, giving copies to your friends). Because of this, I can't go into specifics, but it has been discussed in the forums recently. That discussion was more iPod-centric but can apply to other players.

Sync is more or less what you understand it to be. You can do an autosync - puts on content from your computer automatically (all or as much as can fit, you might be able to tailor it to your needs). Or you can manual sync - you pick and choose individually what goes onto your player.

Since I don't own the Zune, I can't comment on actual battery life. The Zune website states 4 hours for video. I imagine it should come close or surpass it by a little, provided that you don't listen to music (as other uses will drain the battery) and you turn wi-fi off. Since you're going on Boy Scout Campouts, I imagine you won't have access to an electrical outlet to charge it. There might be some third party options to add additonal charge using either regular batteries or solar power. If you want to do that, it wouldn't hurt to do some research.