Sure, these sound like great ways to find flaws in ideas. But if you truly want to add value, you should at least come up with a solution or suggestion. If you don't have one, put it down in the minutes as a resolution item for the next meeting.
To reduce the lack of no follow up, ensure that the minutes are sent out to each participant with an action plan and date. Follow up on the status prior to the deadline to ensure people are working on them. One of the reasons why meetings are such a waste of time is because there is a lack of follow up, causing delays in the timeline, and the need for more meetings to follow.