Admin Stepping Down from NetworkQuestions

Our network admin is stepping down and will be disabled from the network in a few weeks. My questions that I cannot seem to find answers for.

1- Our admin has set up our processes, files and manuals. She has conducted surveys for meetings and posts. Will all of her activities be available to the network when she is disabled?

2- Is it possible to edit her login email address to "move" her user to her replacement? I can see I can edit Name and photo but cannot see the option to edit email address

3- Is it possible to export in bulk tasks assigned to this user, to the Super Admin? Or transfer to a new user?

Appreciate your prompt attention so I can formulate a strategy

Tony