I read that the canon 35mm f/2 IS is the lowest aperture lens that also has IS. Is this because a stabilizer at any lower F-stop is not possible, or just because it is just currently outside of our practical technological capabilities? Also, I have noticed longer lenses typically tend to have higher F-stops, for example there typically aren't any telephoto lenses with an F Stop lower than 2.8 (although I haven't explicitly researched this). Is this because it is not possible to make it any lower, or because it is currently too hard to make such a lens with given resources and technology? I would also like to ask the same question with regards to wide angle lenses, the widest I know of to be an 11mm lens. How much wider could it possibly be pushed without being a fish eye lens?
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
There are several questions mashed up here, most of them based on false assumptions.
Rectilinear lenses and fisheye lenses are different and they can have focal-lengths that overlap. As in, there is an 11mm rectilinear but a 15mm fisheye. One does not simply switch below a certain focal. A rectilinear lens has a practical limit though since one cannot have it project 180 degrees, how close it can get to 180 is a matter of cost and design. One on the other hand fisheye lenses can view up 220 degrees wide at least.
A quick search on my site shows there are currently 31 telephoto lenses with F/2 maximum aperture. So telephoto lenses can have brighter than F/2.8 aperture. Remember that the aperture is a ratio of focal-length, so the longer the lens, the wider it has to be for having the same aperture. This makes brighter aperture telephoto lenses more bulky, so if you look at 200mm with F/2 aperture, there are only 3 and they all weigh at least 2.5kg (5 lbs).
Regarding stabilization, there are 17 stabilized lenses with F/1.2 to F/2 maximum aperture, so it is possible even for F/1.2 lenses to be stabilized. It is not a technology limit but an issue of lesser need. The brighter the lens, the more light it lets in, so stabilization becomes less important.