George

I'd keep things as they are until you can do the thing properly. Removing half may destabilise it.

Not typically historically where it's essentially just a stack of bricks with an internal parge coat. But modern chimney construction do have trays at the roof line and at the top of the chimney. Wouldn't worry about it. They just went belt and braces to make it watertight.

Padstones aren't usually necessary for lintels because the spans are shorter (so the reaction loads are less). Looking at that photo, the bricks appear to be solid and not on a perpend joint so shouldn't be an issue.

Usually bedded into mortar with slate to level if needed.

It really needs a structural engineer to do an inspection rather than a builder. Sometimes joists hangers are needed, sometimes skew nailing is acceptable. Similarly for the ledger plate connection (although the single lone fixing definitely looks a bit weedy) and padstone questions. If there's a steel presumably there are structural calculations available so it's not starting from scratch.

Anything is possible with enough cash.

Yes but the use of agricultural land to avoid inheritance tax seems to be a more recent trend. A cap or stronger limits that the owner is actually farming would help.

Agricultural sector doesn't have the cash to pay 40% of the estate every 20 years or so. And the subsequent devaluation of land may make paying an inheritance tax impossible anyway. Realistically you'd probably find that land is owned by large corporations which then becomes landlords for tenant farmers. Essentially the corporations will become the Lords of the modern world. But experience around the world shows that owner occupiers make more efficient use of agricultural land. Actual profit margin is around £200/hectare, depending on many factors. So more like a century or two.

Ehhh brickwork cracks. I'd suspect leaking or broken drains being the most probable cause. Check them, repoint, maybe crack stitching and crack monitoring should be enough. You'll never be able to eliminate the worse case causes from visual inspection alone but they are unlikely.

It'd cause glorious chaos in food production if that were introduced. Mind you, the likes of Dyson and others shoving their money into farmland does make things harder for actual farmers. Value of land Vs income from food production bears little relationship these days.

Are they wobbly?

Thanks - didn't know about the lap screw. Corrugated fibre cement is still a popular choice for ag buildings.

Can I just check my understanding... for square sections you don't put fixings through the crown, only tight into the flat sections. For corrugated roofs it's the other way around and the fixings only go through the crowns.

Oh it just sounded like there was more you could say but I wasn't expecting a name and shame exposé on BuildHub.

Thanks It'd depend on where the internal walls are. If there aren't enough internal walls (allowing full roof trusses to span across and support the dormer) then you likely need steels to provide a ridge beam and dormer support. So it might depend on the internal layout and your neighbours might have something different that does allow it to work.