@horang007
1. Thanks for letting me know, will look into it.
2. Take a read of the included guides. To start seeing traffic coming in you need one of the following three things:
a) Your pins need to be indexed (ping them, use 'social platforms' to crosslink them, seo hashtag & pricetag them)
b) Followers. Use the following script included to follow people in your niche.
c) Start liking & repinning other content to get more users to notice you.
3. I can't give you an exact number of how many you need, and I would be lying if I did. Typically, if you dedicate between 1-2 accounts PER niche that seems to yield the best results.
@jdmeg6
Flickr, Youtube, Existing & Popular pins, though it doesn't upload them to your blog, rather directly to Pinterest with a link back to your blog. It also supports a bunch of features (social integration, re-pinning, auto following, liking etc).