Lufty can merge the Air Berlin slots with their own. By playing with them they can mitigate the issue. ie if they have an AB slot at 0900 and a LH slot at 0905 they can operate Monday using the AB slot, Tuesday using the LH slot: delaying the expiry. Slots are not tied to a particular route.
The EC wants to reduce the percentage to 70%, as does the Parliament. I’m not so certain they will simply give a blanket waiver. Lots of other airlines would want those slots.