Like others have said, it depends.
Many schools are not selective and everyone meeting their admissions criteria will be accepted. No scoring required.
Schools that are primarily holistic in their admissions review will assign scores for each factor they consider.
No. Selective schools usually have far more applicants that pass that first screen than they can accommodate. So they then go on to “shape the class” - deciding what they want their freshman class to look like. This is driven purely by institutional needs and priorities. Finally, they may consider yield in deciding who to make offers to.
For schools with rolling admissions, yes. Otherwise no. The latter have a fixed application date and they’ll start looking at all applicants only after that date. There is no advantage to applying early at non rolling admissions schools.
If you’re asking about EA/D → RD, applicants deferred to RD will be considered again in that round alongside all other RD applicants. Some, but not all, schools may prioritize students who applied in the early round and were deferred.