Interactive D compiler
asm.dlang.org
asm.dlang.org
http://s-macke.github.io/jor1k/demos/compile.html
Of course the total loading time for the website would increase. But if use such a website you stay longer anyhow.
Not sure if you're being humorous, but that doesn't make any sense. There's no 1:1 mapping between lines in a high-level language and the generated assembly instructions, of course.
I agree, then. :) It would be helpful to have the address of each instruction visible, since it makes jumps more easy to figure out (among other things).