But those terms (presbyter, episkopos, etc) are leaders in the form of the "elders" or "wise ones", not priest. Priest implies intercession, which is incorrect in the Christian structure. there is only one Intercessor. One Priest.
If you care to suppose 'priest', why would the writer use 'presbyteros' or 'episkopos' when hiereus is the proper term, used in it's variants throughout the New Testament. In fact, to my meager knowledge, it is the ONLY word used in the New Testament where intercession is known to be involved (ie: Christ as Archiereus).
Wrong. Christ is the High Priest (as in Israel). You "do" recall that there were ancillary priests serving in the Temple?? All offering sacrifices. (And note that Christ is called "Arch" hierus by your own reference).
There is no barrier in Scripture to the presence of others with priestly offices.