2) How to properly challenge a group of high level characters? And I don't mean just combat ones... challenges that get into that range are going to be noticed, and frequently impact the world in some fashion, unless you have a Belinara equivalent to "deliver this package." So if one is not familiar with playing a high level character here, he may be uncomfortable with trying to challenge them creature-wise...and may not want to mess around with lore to do it. If you want a long high level series, it will need to be Lore-stamped, because it's going to be big - and some don't want to mess with that.
I dont really agree with that. Just because were Epic, doesnt mean we dont have to clean our house, and wash our clothes and so on. Epic quest can be on the same scale as normal quests. Just harder, more tougher and more deadlier. It doesnt have to revolve about worlddomination, or planar corruption. But something as "trivial" as infiltring a mountain full of giants, or venturing under the continents for a passage of old something.You can pretty much use all the same quest layouts and just transfer them to a "epic" scale.