I would be quite amused if a player wasn't interested in a setting because they didn't like the weather!
What's important from my point of view is those things that directly influence the players and their characters, during a game. it's your point 4 that's the most tricky and to some extent point 3, which is what I was saying with 'social structures and beliefs'.
I'm not sure why you frame a setting like this as a "problem", and a deep one - although I completely agree with (4), that one is the trickiest and hardest to realise, but you're characterising the setting as a "hard sell"? I suppose to a player group? I'm not sure that's true.
I'm very curious why you think the
technology as a hard design problem - why do you think that's a hard one?
They're designer problems, not of need GM/Player ones.
Most people are used to simple tools of modern, fairly durable, design. And a smaller portion are familiar with iron tools and weapons. Bronze weapons are cast, not forged; cast, then ground sharp. Tempering is a good bit different, too. Bronze weapons are not as brittle, nor as hard, as cast iron, but are more brittle than forge-steel. There should be (for a true bronze age feel) a risk of snapping, and most bronze swords are only stable for thrusing use; there is a significant risk of snapping if they are used as swinging weapon. Further, no longswords nor greatswords due to the bronze being too brittle for long blades. Also, the tech is surprisingly good for many things: saddles are comfortable, chariots can be built with suspensions (Celtic or Chinese styles)...
There are some things even RQ gets wrong... Looking at the GW RQ3 list.
RQ should have only two of its 6 types of sword: shortsword and cutlass. The bronze cutlass is also heavier than an iron one, because it's cast with more thickness and width to stand the slashing use. The broadsword, bastard sword, greatsword, and rapier all are too fragile for swinging when cast in bronze; the rapier is a thrusting weapon inherently, but bronze isn't springy enough. A bronze knife is good for cooking, but not for combat.
Parries need to be more careful, as well... the more brittle blades break easier.
The tech really is the hardest part to design right - combining both the lack of durability and the material limits.
The designer's job with culture and religion can be readily cribbed from historical sources, paraphrased. Tedious, but easy.
Laying out the map, remembering to get the distributions of city/wilds right, and the types of government is a little harder than the culture and religion, because they have to actually understand the intertwining of the religion and culture with government... or just rename realworld ones, say, by mirroring the map then rotating it...
Further still, a good game will explain the tech paradigm.