Can Hordes play as well?
Long answer short: yup. By all means bring your Hordes army along. there obviously won't be a faction coin for you to take away but you still have a shot at the top spot if you think you can take it.
5 x 50pt games in a day???
Obviously you, and several other players would really have to be going some to get 5 in the day but, it all comes down to list choice and planning through your opponents turn. Know your models abilities and have a reasonable idea of theirs. We won't be playing timed turns or games but there's nothing stopping you from doing so if you want to! If you get to 5 games then you deserve the bonus points! (we'll get onto the scoring for the day later)
A few tips for the day
- pre gen some lists. you obviously don't want to spend half the day trying to decide what your lists will be, write 2 or 3 lists and bring the models you need it'll speed up the pre-game setup a lot!
- remember your trench markers and terrain. I won't necessarily have time to sort out spares so you'll be poked if you end up fighting on a bare table!
- read the scenario! At 50 points it may well be easier to win by scenario than going for caster kill.