Confidential data shield, Complete Analisis and Sandbox cuestions

I am very sad about the spanish forum because no one give me support. Now i have to wirte in english and for me is dificult. I think this aucense in the spanish forum is because you dont use johana voice anymore.
Ok now my cuestions
1.- I want to know if Confidential data shield do any mofication in the documents who detect. It because i use safecreative, a intelectual propiety agency who puts a Time Stamp in my documents and i dont want to be alterated because they are legal proofs
2.- Complete analisis haves uefi optión Why is this needed?
3.- Want to know if i can install a app in avast sandbox, use for a while, some days and then use it again whithout install again. For example i install some extrange software today, then shut down machine and then install