Remove some libraries or helpers, problems?

[eluser]Steeep[/eluser]
Hi, I am developing a small project, small in every way, weight, code, files, etc..

But my question arises that if I delete some libraries or helpers unused, this could cause problems or incompatibilities?

For example erase some drivers to manage the databases or delete the library calendar or FTP, I can do it without problems? or this dependent upon one another?

Thanks in advance.

PS: English is not for me :p