Without trying to rub it I just got back from San Francisco where I went to a few SF Beer week events that were fantastic. I think something similar to what they do would be great so here are my thoughts.
1. Time of year that is best to hold the event
Not super important so long as you are net getting rained on. The double ipa festival I went to was in the middle of SF winter, outside and packed.
2. Location - City / Suburbs / Hotel / Other venue
At a bar/venue where people can kick on and there is stuff other than beer for partners would be good.
3. What you would pay to enter the event
The two main events I went to was the gala opening for beer wee and a double ipa festival.
The gala opening had about 40 breweries with 1 to 3 taps each. Each brewery had their own staff here. The event ran for about four hours with a vip hour at the start for press and people willing to pay an extra $10. The basic ticket price was $45 which got you a really nice commemorative glass and unlimited tasting. The glass probably held about 125ml at a guess. This was great as you didn't need to worry about tickets or any of that stuff and the price was high enough that you got people that wanted to taste beer and not people that just wanted to get drunk.
The double ipa festival had about 60 beers poured by festival staff and not by the breweries themselves. Pricing here was $35 I think which got you a glass and five tastings. Tastings were a little smaller at this one. Crowd was much larger but it wasn't as well laid out. People also tended to come drink their five tastings and take off. People didn't hang around like they did at the gala. This one ran for around six hours from memory.
4. What you expect for your entrance fee
See above
5. Would you pre-book tickets?
Provided reasonable information was provided about the event.
6. How long should the event run for - an afternoon / evening / day etc
I think an afternoon should do it. I think you should have the breweries there pouring their own beers but do it at a venue people can kick on at.
7. Is there a place for other things like cider at the event?
I would stick with beer for the actual festival so it's not confused. However, you do want to have food and other things available.
Maybe the SF model won't fit perfectly as the beer scene there is years ahead of where we are here but I'm sure there is something we can learn from it.
