Cool! One of my site's is listed in Bourge Designs "9 websites..." article, so that's good! We'd certainly consider promoting your campaign as a small paid ad.
The project you're doing isn't about zombies right? I've seen enough KS zombie films to last me a lifetime!
To address your points:
1) I think backers would want to know more about you (the director) and the cast. Where have they worked before, what previous films you've done and your experience. I think if they support you, they'd want to see that you'll get it done and that it'll look good.
2) Tshirts and other stationery is a no no in my book! So I'm glad you're not doing it. If you think about it, if you're giving a Tee out as a tier, you're giving out (free) promotion to your film...but in this case someone is paying for it.
Instead how about these ideas:
- Feature a backer as a background actor + give them credits in the film
- How about a backer's name being used as one of the lead characters
- Advertise a backer's company or website in the background to scenes...the list is endless.
3) I mentioned this one already
Best of luck