Wa alaikum assalam Nura,
Other than what is explicitly stipulated for certain individuals in any
pre-existing bequests and the general provision for any needy that may be present 4:8, the Quran recognises 'biological' relationships in the main for distribution of personal wealth. Step children would however be entitled to inherit from their
own biological parents.
INHERITANCE LAWS IN THE QURANhttp://quransmessage.com/articles/inheritance%20FM3.htm Therefore:
[1] Generally no, unless specifically stipulated in a pre-existing bequest and the general provision of 4:8 to cater for the needy.
[2] If two individuals do not share common parents or any linkage through
'nursing' (who gave you suckle - arda'nakum - ridia'ah - 4:23), there is arguably no biological link from a Quran's perspective and thus, a potential marriage would not be deemed unlawful.
I hope that helps, God willing
Joseph