Hello kiran,
I'll try my best to answer all these questions for you.
1) Is there any template close to a Web2.0 look-n-feel available that i can customize/use (something like Yahoo Answers or Twitter)
Short answer is no (not really). I made some templates but they don't quite have that glossy web2.0 interface - but that said there are a few customized Kunena 1.5.3 templates available at the moment check them out here:
www.kunena.com/forum/136-templates-and-d...kunena-153-templates
. But I think you'll have to strip the templates heavily and add
CSS bubbles
etc. to achieve this minimalist web 2.0 feel
2) What template files do i customize, such that i can show a product-specific forum on each product page (vs. default template that has a catalog of forums under a category listed)
This would be quite difficult to achieve and isn't really a templating issue. My solution to this would be to use the Kunena discussbot by ObjectClarity.com (although it does depend on what catalog system you are using - it'll require some kind of work-around I'm sure). "The Discussbot allows you to integrate your Forum discussions with your content. At the bottom of your content items it can include a link to the discussion about each article and optionally include a subset of the running commentary" - like a commenting system under the product but the discussion will appear on the main board too.
Discussion about it here on Kunena.com Forums
and
Demo of the discussbot on Object Clarity's Website
3) Is Kunena scalable so i can have 100's of forums, one on each product page?
It is possible see:
Can I Install more than one kunena forum in my site?
but I'd use the solution to number 2 above if displaying on a product page - it'll look clean and not so cluttered
I hope i didn't misunderstand your questions and hope this helps you out a bit.