How to make table view as the default view of the forum for the visitors and linear view as default to view posts. Also how to remove the 'post reply' link from each replies to a topic and make it visible only on bottom.

You can change the default view in Forum settings → Advanced settings → default_view (set to 1). Everything else id "hard coded" and code modifications would be necessary. But I really recommend to use a common linear bulletin board if you prefer the linear view! This one is primarily a threaded/tree-structured forum.

Alex