Wow... long title.
I'd say that around half of those players, if not more, that are already 52+ are botters. Seems like 90% of the SRO population are botters these days...
Bunwangs might be a little slow for you. At L45, I was grinding on Ultra Blood Devils, and White Spiders, although I was a Pure STR Glavier, with a SoM weapon.
If you're grinding right, using the right skills, on the right mob (of which your EQ can handle) and you have a 0-gap, the only possible way you could grind any faster would be to either get a GT, or a PT (if you don't have one already).
Just try different mobs, I'd say, and see how much % you get every 10 or 20 minutes. If you're doing 10 minutes, multiply that number by 6, to get the % that you would get an hour. Then try a different mob, and compare and contrast to see which one is faster for you...
When you say you grind from 42-45 in 4 days, if you mean, 4 days per level, then I'd say that's a little slow - depending on how much you play a day.
And yes, farming at 52 would be ideal - Penons have a nice spawn, and you get a new change of SoX weapons at that level, if you can afford one. If not, just try to get a +5 or higher, and you should be fine. Try for atleast 40K-50K or more... at the very least, I'd say.