I don’t think D4 will actually have low level content in the traditional sense where you can go back as a high level character and murder everything.
I don’t know if they have talked about it but I always assumed from the way it was described that the zones would have an effective auto-leveling property where the lower level stuff will sort of level up with you so that you can go back to that area and still have stuff to fight.
I do like the idea of target farming, D3 solves this with crafting however I think it’s better to have a fight monsters and drop loot way to get the items.
On the flip side, there is nothing quite as frustrating as being forced to run tons of A1 bounties just to get the RRoG. So I do hope that D4 works on providing a few ways to go about getting some items.
I like the idea that most of the core loot is available everywhere but the nature of an area makes the chances better in some areas.
I think in D4 there are different regions on the map, I’m hoping the regions have different item base types, so if you go killing monsters in that area then on average you get more items with that base type, so if the upgrade you want needs that base then those areas are a bit better but still not the only place.
Not sure about MF overall, I think it’s a design space that introduces more problems than it solves, in D2 it works because some characters have good power almost entirely unlinked from gear - barely a sacrifice in some scenarios.
In D3 MF is linked to your selected difficulty which is probably better in theory because it encourages fighting harder monsters but in D3 the power creep horribly mismanaged this and this mismanagement is definitely something D4 should avoid.