* Wikidata API has not been finalized, and will be rewritten (with some time overlap to allow for migration). See the proposed Wikidata API roadmap, and feel free to make suggestions

by "make suggestions" you mean I can click "edit" of a section and type in any text directly? or there is some dedicated page/forum/maillist to input? (sorry for my ignorance, I'm quite new to MediaWiki developing)

Best place to start - on the "talk" page (at the top), post your comments, and people will reply. Should be the best way to start.

now before implementation begins. Hence - there isn't that much in terms of documentation yet.

P.S. gmail automatically puts your emails into spam because it thinks its a phishing attack (the mail server forwards it as-if it came from you)
anything wrong in my email setting I can avoid being recognized as spam?

I'm afraid there is not much you can do, maybe except using a non google.com account. I had to mark your email as "non-phishing", which sent a copy of the letter to google to examine. Will see if they can come up with something :)