I'm not sure there's an easy answer to that - there's going to be a range of views. Me, I'm happy with the graphic style and your general overview, so I don't need to even see the demo. I'm sure there are plenty of other people on this forum who are of the same mind - you've convinced us already, and we'll take the rest on trust. A lot of people will be harder to persuade, and the demo will be handy to bring them around. The more complete the demo, the more of them you stand a chance of winning over and the more money your kickstarter will bring in.
So, throwing the ball back to you

, I guess it depends how much cash you're asking for - if you're asking for 300k again, I don't think you'll get there without providing a significant demo, including combat etc, and doing a lot of preparatory work with the rpg websites before launching. Even then it will be difficult. The campaigns that seem to get funded for 100,000+ seem to be those from companies with existing IPs or fanbases. From what I've seen, there's a market for biiiiig projects like the Obsidian and Brian Fargo kickstarters, and there's a market for smaller projects like Paper Sorcerer etc. The ones that fall in the middle (more than 50k, less than 1m) seem to find it difficult to get funded.
I'm sure its not impossible though. Perhaps it would be worth getting in touch with a few of the guys who have had successful campaigns (maybe Larian?) and getting some advice? (if you haven't done so already). Speaking to people who've already been through it can only help.