Join Date: Dec 2008
Location: Perth, Australia
Device: Sony PRS-650, Sony PRS-T1, Kindle 3, iPad2, Nexus7v2
No to both questions. The elastic straps hold the Kobo firmly to the back part of the cover which is fairly stiff. As the front cover is equally stiff it would need a very firm grip to damage the Kobo within.
Most covers have a similar system of attachment points and I have not yet read that the elastic straps loosen over time to cause the ereader to fall out.