Questionsregarding low pop realms and hopping

[Strike1st]

Hello folks.
I have been wanting to try multiboxing with WOW for a bit and decided to go for it.

Just a couple of questions and goals

• My goal is to have 5 elemental shamans. "still a beginner".
• Gonna PVP with them for fun mostly.
• I am also aiming to farm rare elites that have a very low spawn rate to collect all mounts. *very very important*
• I plan to have 4 of my characters on the lowest pop realms possible. each on different realm.
• From my experience with realm hopping. it seems that easy. Everyone joins leader realm. is this correct? if no, please explain it clearer.
• Does it matter if I choose low realms even if I happen to choose german realms or spanish " My main is on english realm btw"?
• Anyone know a way to see number of players in each realm to make my decision?

Would this work? If you got any new ideas, please throw them around.