Merry XMAS and Happy NEW YEAR !!

I cant get through the WP team telephone so I am asking you guys.
I received my HSMP like 5 month ago. I got 2 contracts since that. One on 1st of Sep and another one on 5th of Nov.
I am working under umbrella.
The questions:
Do I need to register every contract I get?
Do I need to register my umbrella name and address or every client name and address. Or umbrella name and a client's address?
Is it safe to report employment change that happen 4 month ago or just 'forget' about first contract and register the second one?
I am going to apply on ILR soon and I want my history to be clean at least for last 3 month.
Thank you in advance!