Help to find solution to the next 2 things

i am looking for some plugins or other solutions for the next 2 problems:

1. when new blog is created give the user option to select the blog industry/group/category. if it's not possible, i want to have this option for super admin to assign every blog manuli to some industry/group/category.
this will make all the work more effective and clean.
the purpose is to click on some industry/group/category and see all the blogs assigned.
second, you can send email for all admins based on industry/group/category
Three, you can show some message in the admin dashboard based on industry/group/category and etc...

* i dont want to show the blogs in the front end based on industry/group/category. it's only for backend purpose.

2. when every new blog created, i want automatically add specific(exist) user/users to every blog.
and better, if i could create group and assign specific users to this group and then to set the group i want to be added to every new blog that created.

* i dont that every user that rigiter to the network will be assign to all the blogs. only specific groups or users.