All folders have the same permissions but the icons are different. Why?

screeshot please

What is the blue dot?

it's for virtual album (not sync from galleries folder)

Why do some have manage album photo icons and some don't have this?

the icon is present only if THIS album (don't care of subalbums) has pictures

Why some albums have a red button at the end and some have not?

virtual albums can be directly deleted, not physical albums