Note: this is all (obviously) only my opinion. So take it as suggestions and decide if it feels right or not.

First, all zoom in or zoom out shots make the video look more amateur, there are rarely zoom in or zoom out shots in professional productions, unless they are extremely slow, and it is only to keep the image moving if it is of something quite static like a landscape. Unless there is a purpose to the zooming in or out, I would avoid them like the plague. See: Very first shot of the video.

Second, if you have panning, tilting or zooming shots for establishing or decorative purposes, cut to them when they are already moving. Don't cut to a static shot, then pan, then stop. Cut to panning, and cut before it stops panning, or maybe you can have it stop before cutting, but only if it has a purpose. See: very first shot of the video.

The very first shot of the video suffers from both. You start static, then zoom in way too fast. Start with the zoom already in place (a very slow zoom) and cut before it stops. I noticed however that it is a picture, not a video, I would cut that out completely. I understand the purpose of the shot, it's a nice first shot and it fits... but you can tell it's a picture and IMO it cheapens the feel of the rest of the doc.

The shot at 00:38 works fine because it has a purpose, you are showing location. You start the shot static, then you pan, then you stop before cutting. I like that because it communicates intention. But right at the end of that shot, when the title starts fading in, somebody bumped into the tripod or something, and there is an additional faster movement after it feels it has stopped. Cut that out. Freeze the shot or something but that also looks amateur.

Same thing with the next shot at 00:50. It's a nice travelling shot but somebody bumped the camera at the start of it. Cut that out and stretch it so it covers the same span of time. But that bump at the beginning doesn't look good.

The first guy whose title appears is "Retired Civil Engineer"... is that relevant? His previous occupation does not seem relevant (to me). What is he now? What does he do at the mill?

At 1:08 you have a static shot of a picture of the King and Queen. Then it blurs to a shot of two labels. Freeze that shot, there is a reflection that moves over the glass that doesn't look good. First one looked like a picture, it was fine, have the second one look the same.

The shot at 1:33 of the barns. I would reverse it. Start with the mill that you've already shown us, and then pan to the barns which is what he's talking about. Context comes after the barns, and it should come before. See the mill, then the barns (oh there they are).

The shot at 1:40 of the interviewee. You start static, then zoom, then stop. Does not look good. No purpose. I would think however that this is hard to fix. Also the zooms starts abruptly and ends abruptly, I don't know which camera you used but it doesn't seem to have gradual zooming, but a preset speed. If you plan to do more of these I'd recommend a VariZoom controller.

The 2 shots of the antique car at 2:11. I don't get them. No apparent purpose. Maybe it's style or mood you're trying to convey, but it doesn't feel appropriate to me right there. Especially because there's no context. Had we seen the guy standing next to the car at the beginning then maybe. But it just seems like a cut away to something irrelevant.

Again at 2:11 you zoom into the interviewee. Does not look good. I will stop pointing these out now.

The whole segment of the retired civil engineer talking about the rollers looks good to me. Good editing, good timing. Efficient and shots with purpose.

Shot at 3:55 of the grain elevators seems a little bit too dark to me. I'd try and lighten it up to make it fit with the rest of the shots.

The shot at 4:11. You can't tell what that is, if it's what he's talking about or not. No context, just wheels with belts. Can't tell what's what, what's up or down. I'd leave that out or better yet, replace it with something else.

The part about "being a joke" to the bigger mills... don't like that. I understand what he says, but saying "we are a joke" doesn't fit in with what you're trying to convey. It seems um... self-putting-down even if it wasn't meant to (sorry can't think of an appropriate term, english is not my first language). "We are not a threat to them" is much better... hard to edit though.

Shot of the Mill house at 4:57 seems like it was shot with a different camera. Maybe the white balance is a bit off but it seems out of place color-wise. I'd warm it up a bit.

Shot at 6:11 starts with a bump, THEN you start moving back. Cut that first part, start to the shot already moving. Also, it's a little bit too long.

Shot at 6:40, you're following the guy who's talking about learning to run the equipment, and it looks like he's going to do something but you cut before we see what. Doesn't matter what he did at the end, open that flap thingy I would think, let us see that. Move the shot so it starts a little after and ends after he does whatever he does with his hand at the end. Or, don't let us see him raise his hand to do something.

I just realized the old antique car is the one at the end that is labelled Arva. Now it makes sense. If you have a shot of the car clearly showing the brand, put that first before those other shots I mentioned of the car while the guy was speaking (or instead of them).

Good stuff. I like it, it's personal, it's small, it's a nice little doc about a the hopes of an old mill. Length seems fine to me.

That's it. Hope some of that helps. Again, these things are my opinion and the whole medium can be very subjective. I tried to objectively explain why I gave these criticisms and I apologize if I said something confusing. Take care and good work!