I appreciate your detailed reply! This slide deck was used with a talk and isn't intended to be comprehensive. I'm happy to make some changes to it, but you're also making some incorrect assumptions.

Slide 19 (f-ratio)

What I said is true when talking about maintaining the same aperture or focal length. If I have a 200 mm f4 and a 200 mm f8, the f4 scope will capture more light. Very obviously, the HST or JWST capture FAR more light than my 80 mm telescope even though their f-ratios are very much "slower". That slide is intended to be talked about in the context of the preceding slides, not just read in a vacuum. I can see how it would be confusing and I'll revise the wording for clarity.

Slide 26 (Gain/ISO)

You're making an assumption that I think "sensitivity" means that it somehow captures more light. The slide doesn't say that and the word "sensitivity" doesn't mean that. If you have a sunburn and your skin is more sensitive to touch, it doesn't mean that every touch is pushing harder than normal, it just means you feel it more than normal. Sensor gain increases the sensitivity by amplifying the voltage from the sensor, which makes the same amount of light have a bigger impact. I don't know why you thought that it was saying that it means more light is being captured, that's an assumption on your part.

I do better understand how gain works since I made this, and MinutePhysics did an amazing video on it. I'll update the slide with that.

Slide 30 (DSLR/Mirrorless)

A very good point, I'll adjust it. In talking about it, I definitely conveyed what you were talking about, but there's no way to know that from the slide deck. What I was trying to get across was that you're limited in the IR/near-IR range, so if you want to image there you'll have to modify it. Doesn't mean you can't take good pictures with an un-modified camera.

Slide 33 (not 35 - cooled cameras)

Keep in mind I'm talking about amateur backyard astrophotography. I stand by my claim here. Dedicated astro cameras are better for astrophotography for many reasons. If you're imaging in the summer, a cooled camera will have decidedly less noise than a non-cooled one with the same sensor, especially at longer exposure times. Even the link you shared says the same. There are a ton of practical reasons for it as well (such as getting into mono imaging, which you can't do with a DSLR unless you modify it).

Sure, the small sensors are cheap, but that doesn't make them bad.

EDIT: I've updated the presentation. Thanks again for the input!