I have come accross vi-style keybindings for Emacs, but my past experience in mixing Lisp based config in .emacs file for enabling various modes etc., hasn't been very pleasant so far.
Read several articles on Emacs + Erlang, but is there something that might be slightly easier for folks familiar mostly with vi (and who are unfamiliar with Lisp)?
The entire set of possibilities (keybindings) is quite overwhelming. Is there a condensed key-map/shortcuts reference specially relevant for Erlang development?
Just use vi and a command line. There are numerous people doing that and it seems to work just fine for them. Even though I use Emacs, it is not the Emacs-erlang interaction I use. Rather I usually just have a separate Erlang shell and then I load modules in that shell with the l() command for interaction.
Answering your questions one by one:
Debugging in Erlang is funny. Firstly, if your program is kept functional you will find that you need much less debugging to figure out what the program does incorrectly because you can simply write small tests for each of the numerous functions to test its correctness. And you can add those into unit-test frameworks.
As soon as you add multiple processes to the mix you will find that traditional debugging doesn't work anymore anyway. The trick is then to trace and assert, and you will need to learn a way to read programs without running them and see where they go with a debugger.
That said, try to execute debugger:start() in an Erlang shell :) There are also the tracing systems and redbug, a 3rd party tool built on top of them (part of the eper suite).
Profiling can be done with one of the 3-4 profilers: cprof, eprof and fprof are all slightly different in scope and in how much impact they have on your program and if they can be run on a production system or not. I tend to use eprof and I have a knob in my program which will spawn an eprof and then attach it at program start.
Try appmon:start() in a shell.
The standard vi-way of browsing large code bases is to create tags-files so you can jump to the definition point of the thing-under-the-cursor. Emacs can do the same. I have a make tags target to create these files so I can easily make jumps around in the source code. When jumping you have a stack of the former jumps so you can return to the point you jumped from later on.
Finally there are tools like xref which can be worked to create call graphs and find odd things in the code. It will require some coding on your part, but it does provide you with the necessary tooling.