We are ALL ambassadors for Christ, every single believer.
No priest found in any of those. presbýteros properly, a mature man having seasoned judgment (experience); an elder. [http://biblehub.com/greek/4245.htm]
The Greek word for priest is hiereus and is never used for New Testament church authority or leadership. It is used for all believers.
1 Peter 2:9 But you are a chosen people, a royal priesthood, a holy nation, God's special possession, that you may declare the praises of him who called you out of darkness into his wonderful light.
Written by Peter no less!
>>You'll have to explain your reasoning for that one; I'm not even sure what that means, as worded.<<
1 Timothy 3:2 An overseer, then, must be above reproach, the husband of one wife, temperate, prudent, respectable, hospitable, able to teach, 3 not addicted to wine or pugnacious, but gentle, peaceable, free from the love of money. 4 He must be one who manages his own household well, keeping his children under control with all dignity 5 (but if a man does not know how to manage his own household, how will he take care of the church of God?),