Hi @jayavinoth,
Thank you for this nice review.
Please note, wpForo doesn’t use post types. wpForo is designed for full-fledged professional discussion boards with millions of topics and posts. Post types are stored in wp_posts and wp_postmeta tables, if we use post types forum will overload WordPress resources. wpForo use separate tables for topics and posts, thus it works very fast and doesn’t make heave WordPress. Forum can be tracked as a separate CMS, it’s a large project which may have millions of entries. Keeping such a large project in separate tables is a good way to keep WP and other WP plugins intact. Those performance will not depend on size of your forum.
wpForo generates own SEO tags in headers, it will also generate own sitemap in near future releases. This is already in our to-do list.