It all depends on how well they've managed to balance everything. It appears their goal is to reward players who manage to focus on many different aspects of the game. The Eureka boosts require that you perform quite diverse tasks, and since they give you half the tech, it is probably often worth grabbing them. Also, many tech boosts require that you have reached a certain point in the civics tree, so if you go all out science and neglect culture, you end up paying double for later techs. If this is done in a good way, so that there are still many possible progression paths through the tech tree, it can be interesting. But it might also be that especially the early game quickly falls into a pattern of always teching stuff in the same order.
We must admit that you can also play Civ4 with pre-determined tech path and consistently win on Deity, especially the most hated (for me) Cuir-rush route or Lib-route. I mean, there aren't many variations in practice.
I can see that in Civ6 boosts are, indeed, making you want go and do everything at once and there always are huge opportunity costs associated to unfocused play. I would say that this is good by design. You can tweak it forever, of course but it would pass Concept Design Review in my line of work.
I get the feeling the AI won't be able to handle 1UPT. They've also significantly changed the zone of control rules to make warfare more interesting, but I fear these changes will give humans an even bigger advantage, since they allow quite a lot of tactical tricks. It appears they are trying to balance easy warfare with other penalties, such as massive diplomatic penalties and (possibly eternal) extra unhappiness in conquered cities. That is bad.
I can't add much to this. You are breaking this down to what I fear will be the case in the new game. But in Civ4 AI is stupid with its movement too. It is only that you can clutter much more power into an SoD and make use of Deity bonuses and that is why Deity AI can prove to be challenging in practice. If they make flanking bonuses higher for the AI, the fight could be more challenging. I just want to say that I never found Civ4 AI fights smart either.
Great Scientists mostly give you eureka boosts to random technologies. This is absolutely horrible. You will be picking up most boosts in any case, so if you want to use a GS for a slingshot, you have to roll the dice and either get basically nothing, or if you are lucky you get the boosts that you need. To make sure a GS benefits you, you have to unlock all the boosts you are about to unlock for the era before you trigger the GS, which means no fast slingshots. The option to go for lucky slingshots will be especially bad for HoF or GOTM games.
I wasn't aware of this. This is plain bad. We can only shout and hope they will constraint randomness to much more acceptable level. Maybe we must accept there are no more bulbs as they were. I always found Civ4 bulbs a bit OP. On the other hand in Civ6, you can buy Great People and limit the random factor which one you'll get. I hope there will be a viable strategy around Great People.
I like the idea of spreading out cities, limited wonder spamming and limited numbers of districts. We'll have to wait and see how it turns out in practice.