Settlers
There should be an interface to assign settlers to tasks, so you know who's idle and where you need to allocate people (since they seem incapable of doing it themselves).
Likewise settlers are being allocated to things like trading stands - but whenever I return to that settlement some stands are empty.
As far as shops are concerned it says in the description that building these provides an income based on number of settlers - but I've had up to 20 settlers at Sanctuary Hills and seen no extra caps (unless it's not telling me about them).
And we shouldn't have a limit for things like defence being only able to allocate a settler to a guard post if there's no other settler currently standing on it.
Settlement building
The build-area wall is bothersome, especially in some areas like Jamaica Plain. Not sure why such a low physical limit was placed on it - whereas others are huge (eg Starlight Drivein).
Fence building is a total pain in the a$$ if the ground isn't perfectly flat - which it isn't, most of the time. I can rotate two ways (clockwise & anti-) but not in the vertical plane.
Walls and roofs - the "snap-to" (adjacent) function can be really irritating. Would like to be able to turn it off.
Also it's annoying to bring in a new settlement with limited scrappable items then having to go to another settlement just to allocate a supply line.
When opening up a new settlement it usually immediately tells you there are two new settlers... except they're not there. It shouldn't give a number until people actually arrive.
I should also be able to allocate settlers to repair stuff in the event of an attack I couldn't get to because I was on a quest and couldn't fast travel = eg put a person in charge of each settlement for when the "chief" is away.
Settlement events
These happen too often (seems like all I've done for a week is take care of kidnap victims and ghouls & raiders threatening my settlements) - and nowhere near enough variety!

Crafting
While I like being able to modify weapons & armour I don't get why I can't scrap or modify Legendary items.
And also why we can't build weapons and armour from scratch, Skyrim style - which I was really expecting before game release.
Miscellaneous
Decorative items like vases placed on tables, windowsills etc have fallen through them whenever I go back to that particular place.
Why are the settlers vegetarians...? I have Brahmin at several settlements but can't get milk or meat from them? What are they there for, then?
Thanks.