Sharepoint Cleanup

[Deleted]

We are running out of space on our tenant and currently in the process of expanding storage.

Can some one please let me know on below 2 points?

1. How do i get item level inventory from Site Collections/Sites/Subsites to see what kind of documents are consuming space?

2. Can i configure our SP Tenant such that any user uploads files/folders to sites/sub-sites/document library>xxx.MB or XXX.GB i get alert and ask users to use OneDrive to store such documents since OneDrive are with unlimited storage?

Appreciate your thoughts 

[#2]

My 2 cents here:
1.) You only have the Storage metrics page that allows you to browse in the site collection hierarchy and check the weith of the items stored there
2.) No, you cannot