i can see how this could be useful but i would like to add to this suggestion to say that the voteing on the comment should not reflect the users votes left maybe a "rate this Comment" thing would be better where a member could click on a 1-5 stars

I see what you are saying. Then perhaps it could be turned around this way: instead of just Questions maybe the first entry should have a "type" variable for example optionally be Either: TYPE: Question or TYPE: Suggestion

How about a likes/dislike or a thumbs up/thumbs down for comments?

the thumbs up/down should be an option but it should not replace the ability to vote on comments because as stated, sometimes the answer is more important than the question