Drgwen says:
... we are a civilians working for an NGO, the Institute, and we operate in a single region. ...
Cool, we will use that as a basis and define more from there, as it becomes relevant.
Drgwen says:
... I don't actually care what region or country we're in, but we can decide that if it becomes important. ...
As soon as we need to deal with the government it will become relevant; as soon as we need to deal with the locals it will become relevant; as soon as we need to describe what part of our world connects to what in the other it may become relevant, in as much as it will define, for example, if we have skyscrapers where we are (absent input from the players I rolled some dice and got 'skyscraper' vs 'hills and caves', so, unless we choose to change that, we are 'not rural'. :)
Drgwen says:
... I am fine with either speficying items in advance or going with BitD style. ...
We can always go with a mix. I do this anyway in most games, BitD just formalised it. Define as much as you need then fill in the remaining stuff when it becomes relevant.
In
Blades is can be a bit of a head-scratcher when players say they have armor when it was not mentioned before (even on previous hits), but that is something we just have to live with and try not to contradict in earlier character description. Armor is not retroactive, you don't get back HP from previous hits when you declare it, those hits were clearly in unarmored areas, or something.
Drgwen says:
... But we have to declare our Speed in advance! ...
Yes.
You say how much you are carrying when you enter. This says how fast you can move and react. That is the amount you brought with you, this time, it does not define anything about your character's physicality.
Drgwen says:
... we can decide to exceed those limits and change our speed ...
Yes, if you pick up more stuff you will be slower, if you drop everything you will be faster. Update the sheet accordingly.
Drgwen says:
... haul back lots of loot ...
Up to 8 loot each (it you empty your pack of everything else), unless you make plans to handle more (bring a vehicle or (find) a wheelbarrow?).