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Voting to close this question as it lacks discussion context and is thus impossible to answer. Furthermore it is three questions in one. I recommend asking exact one questions per question, with necesarry background details and information to make questions answerable.
The question still lacks the context, like source code, projects, etc. discussed. You can set variable in Solidity with assign = operator. Otherwise I cannot give further direction in this point.
=
operator. Otherwise I cannot give further direction in this point.