Where can you find Jah & Ber runes, i've looked at the countess rune drop ratio's and noticed these where not in her looting table. Other then odd chests in act 3+ in hell settings where can u find these ?
Someone else with more knowledge might have to back me up on this, but I believe the Countess can only drop up to 'Ist.' Also, as far as rune-harvesting goes, you just have to kill as many things and open as many chests, etc. as possible; I don't think your MF% has anything at all to do with rune drops (as they're not in any treasure class, they sort of have "their own thing" going on). The Cow Level and Worldstone Keep/Throne Of Destruction are some good places for killing lots of stuff and getting some good loot.
The Countess can drop up to Ist relatively often, when compared to the highest rune she can drop, which is a Lo, which is extremely rarely.
You are correct... MF has nothing to do with it. The more people in a game, the higher the chance items will drop, which includes runes.
Other than areas with lots and lots of monsters, you can also open special chests, like those in Lower Kurast in the huts by the large campfire(s), and Mephisto's chest, and the superchests in level 85 areas like Pits level 2 and Ancient Tunnels.
A 4os eth CV can fetch a Jah/Ber easily on west ladder. Arachnid Mesh can fetch you 3-6 HRs depending on the defense (1000 hell meph runs with 400MF almost guarantees one arachnid). Alternatively, 3 keysets can sell for 1-2 HRs too.