What makes you want to go to a store? Is it based on price? Or a good vibe about the place?
When I was really into wargaming, it was the models on display, and the awesome gaming tables that keep me coming back. As well as the local wargaming community and regular casual games. However what kept me buying was good prices. Once they went up, I stopped buying. And you can only maintain interest in a hobby you can't afford for so long, even if the models are great.

All the above goes towards a good vibe - staff that are actively involved in the hobby for their own enjoyment that are happy to sit and paint with you and chat, without trying to sell you things constantly (those were the days!), really make you feel like part of something.
what would you like to see going on in the store?
Everything I can suggest you've probably thought of already, but a quick list would be:
- Intro games
- Tables for friends to come in and use for various games
- Friendly campaigns and competitive tournaments
- Painting/modelling tutorials
- Competitions (painting, modelling etc), maybe put winners entries on display
- House rules (and maybe even silly fun games using house rules, i.e. squiq farm survival

)
- -->!!!Specialist games!!!<--
- Sales. Seriously. In normal retail sales are commonplace, but you rarely see them in hobby stores these days. When I was younger I remember GW having a sale day, and something like 200 people turned up to this tiny little store, there were buckets of paints for 30p each and all the models I couldn't afford normally were suddenly within my financial reach. The Christmas sale was an absolute frenzy too.
do you like to be emailed weekly and told what's going on or do you get enough of these emails from retailers already and would prefer a more offhand approach generally?
I guess an opt-in newsletter isn't a bad thing.
what products would you like to see in a store that you can't buy at a Games Workshop store?
Cheaper terrain and better value materials and tools for scratch-building. Small amounts of electrical parts for conversions maybe? And again, specialist games.
what lines would you like us to stock?
Can't really say, the only wargame I ever really got into was 40k. I used to play a fair bit of Magic the Gathering too, and from what I've seen there is some overlap between the two communities.
how far do you have to travel to the nearest high street shop to buy what you're after?
I used to have to go to Oxford (about 18 miles away) by bus, so purchases were few and far between. When I was much younger and first into 40k it was only a 5 minute walk down the road to GW. These days I don't wargame at all, but when I did a year or two ago I just ordered online because it was cheaper (25% discount) and more convenient.
how far are you prepared to travel and what would it take to encourage you to pop in and see us?
N/A see above. If I had a car AND was still gaming, I'd say 30 miles is about the top limit, if there was a great club and I had friends there. Just to make a quick purchase though, I think 10 miles max (if I had transport).
In store events - do these encourage you to come in?
Not really. They did a bit when I was younger, but I generally preffered to take a friend, turn up and be able to play a casual unarranged game there and then with whoever was around (arbitrated by a staff member if there was one free, sometimes they even joined in). The problem with 'events' was that people were too unreliable. You'd turn up with an army and be the only one there that day. Or too many would show up and there wouldn't be room for you.
Should we run a gaming club? Perhaps with extra discount for members?
Yes to the first and..maybe, to the second. I haven't run a store so I don't know if it would be economical. I think having good gaming tables (and maybe some small in-store armies for people to use if they don't have enough models) is enough incentive for members to keep coming back. And people who can't join the club might feel put out that they have to pay more.
Would you like late night opening during the week? Maybe so you could pop in after work for instance?
A very good idea. Being open during work hours only is a bizarre modus operandi I've never understood. Ideally if there's enough demand you want people to be able to turn up at 6 and have a decent 2-3 hour game without having to pack up halfway through.
On top of the above I would also definitely recommend some kind of instore ordering system (prefferably an electronic catalogue) so that people can browse all your ranges easily or look for specific parts. Or at least have a catalogue on a shelf of parts you could order in. The option of home or in-store pickup is handy too. That's how I used to order all my BFG stuff from GW. I always wished they had an electronic (searchable!) copy though, which would have saved a lot of page-flipping and form-filling!
I hope that's slightly useful to you!

Good luck with the store, I wish you all the best!