(Originally I wanted to ask via web-IRC but I am too thick to be able to use it.)
Link: https://github.com/barcharcraz/VisualNimrod
It's still a very early WIP.
I've been testing it on and off with Demos (the author, he's on IRC). It wont screw up your IDE in my experience (YMMV). In order to build it you will need to install the visual studio 2013 SDK, and the debugger doesnt work OOTB, but Demos might be able to point you in the right direction.
Q1: yeah it is safe to try and can be removed at any time. Expect the IDE to crash when you try and close it sometimes, it is a race condition that I am trying to track down. Q2: Sure, I can have this in the readme by tomorrow (August 9) at the latest Q3: Kinda, it uses the built in native debugger and compiles with --lineDir:on and --debugInfo to get symbols. Stepping through non-generated C code should work fine, and stepping through nimrod code works as well, aside from some minor annoyances (the locals window has more than it should, names can change, and the function signatures in the backtrace window are cish). Breakpoints should work, and if they do not try {.emit: "__debugbreak();".}
Edit: the instructions should be up. Be sure to report any bugs you encounter!