Social Media Sharing Buttons concerning the Chinese Great Firewall

We are about to build a multi-regional website that targets users in China and other places. However, a concern was raised about the use of social media sharing buttons. Since China blocks common social media websites like Facebook and Twitter, we fear that showing buttons with their icons on them will cause China to block our site. However, we do want to allow users from other countries to share our website to these social media websites.

So the questions are:

  1. Will these social media buttons cause our site to be banned in China?
  2. If they are not banned, will they affect rankings in search engines?
  3. If the localised version (zh-hans) does not have these buttons, will it helps? However, the homepage in default language (which is not Chinese) will still have them.
  4. Will there be a difference to use sub-directories or sub-domains for different languages, since sub-domains are usually viewed as a different site?

Any suggestions are welcome.