When wanting to print a few variables quickly I usually use @show var1 var2 which does this very nicely. And if I want more elaborate printing I don’t mind writing it with join or string interpolation like println("First we have $v1 after which $v2 comes").
No, me too. The default behavior is more general, as removing spaces is harder than adding them. Still, coming from Fortran and having to print numbers all the time, I prefer the Fortran behavior of adding spaces and a new line in the simplest printing command. Something I can live with, though.
I agree with @albheim here, it seems like the wrong tool is being used. If you are printing variables just for debug (or any kind of human assessment), then you probably should be using @show instead of println. If you are printing variables in a specific format (possibly to be read back by a program), then you do not want for the function to take any liberties with your input.