'Suggested edit queue is full' always means there are too many pending edits in the review queue. If you encounter this, there's nothing you can do about this (with one minor exception - if you have between 2k and 20k reputation, you can help reviewing suggested edits, which decreases the queue size, in order to suggest an edit to a tag wiki or tag excerpt yourself).
The examples you mention about commenting and voting also provide potentially misleading information in case you're suspended. Your lack of reputation is not the problem, the suspension is. You simply can't expect Stack Exchange to optimize the experience for suspended users.
Also, suspended users should not suggest edits, not even when logged out: Anonymous contribution (without an account) while suspended? One of the points of the suspension is that you can still use the site, but only in read-only mode, because your 'write' actions have caused trouble in the past.