Hey there, Leon ... I love the Corbin Fleetliner Saddlebag look on the Slingshot, however, I do not own a set at this time. I cannot personally attest to a fix for either of the issues you inquired about, however, doing some research will lead you to discussions on this topic out there in other forums. I believe those discussions will outline a course of actions that you, as an end user, could perform to resolve, or extremely mitigate the issues. The sad take away, is that Corbin doesn't appear to have a strong customer service etiquette and end user is left in a lurch post sale. It also appears to me that the quality assurance program with Corbin is fallen into a slump.
These things aside, they do make a nice looking accessory, albeit expensive and not without it's quirks. If you're willing to tinker, it seems that these quirks can be worked out.