I am going to learn Lisp using Emacs Lisp instead of Common Lisp or Scheme, because I already have Emacs. Emacs already contains a complete development environment for Emacs Lisp. It includes an Emacs Lisp compiler, editor, and debugger. Everything is well-integrated.
>>1
What Emacs Lisp gets you is a single address space (ala Genera), and a large maintained (that is unstable) standard library; the points you mention most members of the Lisp family have and have better (e.g. SLIME, Edwin, DrRacket). This is largely irrelevant however; when you're first getting started the most important thing is to stick to whatever you choose, and practice regularly.
... a large maintained (that is unstable) standard library ...
Why does large and maintained = unstable?
>>3
Even fixing bugs causes API instability, and the maintenance of GNU Emacs involves far more. TeX and Metafont are exemplars of a proper balance.
>>2
Will I be able to use Emacs Lisp for SICP?
Can I do 3D game programming, Android programming, and create web apps using Emacs Lisp?
>>5
If you plan on studying SICP first than you should probably just use MIT Scheme, or Racket. Beyond this you should probably entirely ignore what you want to do when first learning computer science, and just focus on computer science. If you learn correctly your skills will transfer to other languages, and tasks.
Can I do 3D game programming, Android programming, and create web apps using Emacs Lisp?
Elisp can interface with C by emacs modules and emacs can run as a daemon.
In my experience, learning (Common) Lisp before Elisp makes Elisp a lot easier to understand.
There are far more books for learning Common Lisp and Scheme than there are for Emacs Lisp.