Should I abbreviate the author names due to the page limitation? While I am writing the references for my paper, I usually copy and paste the bibliographic information and use it directly. AFAIK, most of them are in the full version, meaning that all the author names are spelled out, e.g. James Rhianna Smith. (They can be really long!).

Also given the fact that some conferences do have a page limit (e.g. 6 pages maximum), directly using those tedious full names is sometimes a luxury I cannot afford.

Under this type of circumstances, should I shorten the author names?
This is almost always dictated by the style guide of the journal/conference/whatever to which you're submitting. Check with them, or better yet, use a bibtex style definition file provided by them (e.g., IEEE).