What are the changes required to be done to database schema in order customize askbot like TrueShelf

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I see that website http://www.trueshelf.com is done over Askbot. I too had similar ideas:

Some of them are:

1. Have multiple buttons to post topic, question, review etc,,
2. Have an hierarchy in Tags or something like categorization: Like Parent Child relation.

What are the changes to the datamodel that needs to be done? What were the changes done to Trueshelf in order to achieve this? Should I create separate apps or modify 3rd party software. Any pointers regarding this is greatly appreciated.