1: I'm an Emacs guy. That's what I learned in 1983 and it's the only one I still kind of remember. However, day to day I'm in Webstorm or VS Code, not Emacs :) I did learn Vi's two modes: beeping and not beeping though.
2: Spaces. Interesting that I don't remember anybody warring about this one back in the 80's or 90's.
3: Unix. Does Windows qualify as an operating system? I'm showing my prejudices there. I'm a Mac user so I typically only interact by choice with BSD Unix on the Mac or Linux on one of my Ubuntu servers.
Still have my fingers crossed to see nuclear fusion in my lifetime. If so, that would be a game changer.
Since you use a Mac, have you worked with Swift?
I started programming in 1976, with the first program I worked on (as a contributor) was Oregon Trail on an HP minicomputer used by TIES. I used to use emacs, switched to vi many years ago ("it's too late for me; save yourself!"). I tend to use tabs, but I don't care; I care about consistency. I'm a Unix guy; and my machine at home is a Mac. I live in C++ day-in-and-day-out and I envy you for escaping from C++'s clutches.
I did a small amount of Objective-C a few years ago but never tried Swift.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.