I found an old half-finished book of mine, and I was thinking of rewriting it with a new plot. However, I am faced with the decision of either having one main character or by having more than one with the chapters switching between each POV. Would you find it confusing as a reader if I were to use the chapter switch? Should I just be "safe" and stick with the one main character? Personally, I'd like to use the more than one character as a main but I don't want to confuse my readers.
Chapter switch? No I wouldn't be confused. Personally. I'm doing this with my current novel too...just let their thoughts/narrative have differences.
as mentioned above, it's done all the time, so all you need do is do it well enough to pull it off successfully... since you don't seem to be familiar with what is a pretty standard technique, i strongly suggest you study how the best writers of fiction go about it, before attempting it yourself... you may need to upgrade and increase your reading...
Melvin Burgess' 'Bloodtide', which is based on a Norse myth, does this very well as each character has a very different voice and opinions. Generally I think it's a good technique to play around with, as it allows you to practice using different voices etc. which can never hurt, even if it only helps you to define the one main voice of the story. Perhaps try doing short sections with the voices of other characters and see how well they develop, or fit in?