1. Can I pre-order this from the UK and still get an actual retail DVD/CD sent to me? If so, how? and how much? (£ to $ rate is pretty good at the moment I hear...)
As far as I know, yes you can, through the Stardock online store (just choose to get a physical copy shipped instead of Digital Download). Yarlen should be around the forums soon so he can confirm that's how it works.
2. Is this an online only game? or can I play something along the lines of a story driven campaign on my own? ...and will there be a LAN co-op style option (ie, 2 human players teaming up against AI enemies over a LAN for skirmishes or maybe a story)
By now we've found out that there won't be a heavy story driven campaign I think (there are some recent threads if you do a little digging). We basically get a very big sandbox to play with. A lot of the features are not in the beta (the final release is supposed to include some sort of a galaxy generator/creator so you can customize your game however you want). That said, I'm pretty sure there's a LAN option (been a while since I actually checked

), and there is definitely co-op play (you can even ally with AIs through ingame diplomacy!)
3. If I pre-order today will I be able to play the game today?
If you preorder through totalgaming.net with tokens, yes. The caveat here is I believe that's digital download only, so I don't think you'll be able to get your boxed copy if you go this route. Someone correct me if I'm wrong.
4. Is the Beta online only or can I play on my own?
LordMalice answered this one for you, you can play the Beta single player, but the AI is lacking punch

EDIT: Gezus, Blair

What were the chances..