I am a noob so pardon me if I am asking anything that sounds stupid/
crazy/screwed up. I wanted to know, if I can just install it in only
in English, as I will never be using any other language in my life.
Also, can I install this and customize the code for my requirements,
i.e. add, remove or modify any of the modules as per my needs?

This is my first time with an ERP system and that too an open source
one at that. Thanks a lot in advance.

Regards,

Venky

Thank you for your interest in CK-ERP.

Yes.  You can setup CK-ERP with English as the only installed language.  
In fact, this is the default setup.

CK-ERP is GPL'ed.  So if you abide by GPL, you can customize the code as
you think fit.

However, I like to draw your attention to a standard message listed at
the index page of every CK-ERP module,

*"If you re-distribute this module (modified or not), it is your moral
obligation to display this index page exactly as it is or as translation
into a different language without loss of meaning. Failure to do so is
strong evidence that you intend to defraud users by concealing critical
pitfalls and/or shortcomings of this module."*

At the same time, you are most welcome to contribute your customization
back to CK-ERP's main codebase, if you are so inclined.

Best Regards,
CK