Login Items SpeechSynthesisSever

Hey! Well, I did a check through previous posts, which had vague answers and left me hanging.
So here it is, 3 basic questions concerning 'login items'

1) -Which of the basic login items are safe to remove, ie, (,
-iTunes Helper
-Microsoft mouse helper
-System Events
-SpeechSynthesisServer

2) -I can't find 'SpeechSynthesisServer' anywhere on my Mac when I do a spotlight search, where is it, and can I get it back into the login items if I remove it?

3) -Do I need 'SpeechSynthesisServer' for using the 'Text to Speech' program that is in my preferences window. I use the 'text to speech' program occasionally to read /listen the news online.

I also have a wireless microsoft mouse, but I am not sure if I need the 'Microsoft mouse helper' in order for the mouse to function.

Thanks,
Scott