[unknown] Hi Sorry its not possible link one account with other accounts, system does not built in this way.
Regards
[unknown] Hi. Regarding point 2 I believe You can use custom profile fields to handle this. It still means that You will need a predefined fields for Wife, Family, etc. But this way it can be done with current functionality.
[unknown] Hi I am afraid registration could not open other profile and linked, Sharing information and linked them with other profile makes breach in security and privacy.
[unknown] Hi You can use the link URL as you shared in the profile. Sorry system does not support multiple login like in gmail. I will share the feedback with development team for further investigation.