Kostas

An appimage is basically a bundle of all the required libraries dependencies and the actual application you want to run. Its convinient for the developers since they dont have to package their software for multiple distibutions (debian, arch, suse etc). To have it behave like you are expecting (ie be double clickable to run and searchable) you need to make the file executable (either with chmod or a right click menu if your disto has the option) and create a .desktop file (either manually or using an app like Appimage Launcher)

This may sound complicated but it is pretty easy. Though I find it an unecessary hassle as well. Here is a guide with more info as well : https://itsfoss.com/use-appimage-linux/

Oh wow ok. So ios firefox is webkit based? Weird stuff.

does firefox not have an IOS version? It might not have an addblocker out of the box but, in android at least, it supports addons and thus ublock origin.

If you are familiar with Blender and F360 you will have no issues producing models to print. Maybe some mesh fixes but most slicers will manage to produce something printable if there is nothing too egregious. Dealing with overhangs, print tolerances and fine tuning will all come when you start printing, there are some pretty good links posted here already. Prusa even has some ebooks (some free, some you can buy or be active on printables to get) that may be useful (they look to be but I haven’t checked them out myself). What excactly do you mean by hardware recommendations/tips? Are you looking for printer recommendations, setup suggestiong (enclosures for ABS printing, Rpi and octoprint to control/monitor etc) or tools/materials? In any case most of these will vary depending on what is available to you in your area but again when you start using your printer the needs/areas to improve will become aparent. I really would recommend you dive in and ave fun. Any trouble you encounter along the way there will probably be resources to help and, if not, asking here will more than likely get you most of the way there.

Are you looking for CAD tutorials or printing/troubleshooting ? A good place to start when your prints don’t look like they should is the simplify3d troubleshooting guide. As for the design aspect, what software do you want to use?