(i) Keepers

(ii) Two hebrew words are used...

(1) Shamar (8104) - a primitive root; properly, to hedge about (as with thorns), i.e. guard; generally, to protect, attend to, etc.:

(2) Natar (5201) - a primitive root; to guard; figuratively, to cherish (anger):

(iii) Church leaders or those in positions of authority to watch over others.

(iv) (1) (a) 5:7

(b) 1 Pet 5:2

(2) (a) 8:11

(b) as above