Questions about splitting itunes library

Hi Everyone,

I am trying to decide whether to split my itunes library or to move the entire library to an 3 TB external hard drive. My imac is running out of space & a lot of that can be attribtued to my itunes library taking up 169 GB of my 500 GB. I have seen some posts recommend splitting the itunes library and just moving tv shows & movies because of there big file size. I have seen some posts where others recommend moving the entire library. I'm really torn on what to do? If anyone could weigh in and give me some additional insight, I would be grateful. Also, I had a few concerns that are listed below if you can help. Thanks.

1) I am concerned about moving the itunes library and it affecting the my 2nd gen & 3rd gen apple tv's picking it up. I have read posts that as long as it is turned on that it should still pick up the itunes library. Can anyone confirm that for me please?

2) I am worried whether or not itunes (on an external hard drive) will still be able to sync with my iphones, ipad, and ipods.

3) for the future.....will I still be able to add music albums, movies, etc. to my itunes if it is on an external hard drive?

Thanks a lot,

Rog