First of all welcome to the forum!!!
I think all of us have had some kind of slide problems, As for me my floor on the main slide was to tight so the slide would not come back in a little trimming and retiming and all was well. As far as the slots for the rails I used a piece of an old inner tube to block mine I don't think that GS puts anything there as all I have seen has none, Just something left to the owner!!!
Hope this helps you a little!