mount afp drive via terminal like staff profile user
There's some basic misunderstandings of how things are working, so let's clear them up.

sudo isn't a "mode" or a "profile", it's a command that allows you to execute a command as another user (See the man page:  man sudo)

The command su allows you to switch or substitute a user's identity (man su).  So, think of sudo as su- get another identity and then do something.  

Without specifying a user, it defaults to root:

sudo foo = sudo -u root foo.  

This is not limited to the root user either.  User1 can issue a command as User2:  

$ sudo -u User2 foo

Now, Finder doesn't mount anything, Finder will call a function that mounts your device (technically, there's a "listener" function - automount - that waits for a device to be inserted to automatically mount it).  Finder just "displays" it.

This automounter is running with root level privileges which is required to mount anything in the /Volumes folder which is where automount will put the folder to the newly mounted device.  Users aren't allowed to modify this folder which is why you need root privileges; thus sudo

If you want to mount something without using sudo, mount it anywhere you have full ownership, like in your home directory (/Users/username/foo/bar).  Since you have full ownership in that directory, you won't need root privileges to mount it.