Darren 1066

Hi, I live in a HMO and I am concerned for the safety of not only myself but the other tenants that live here. My questions are; 1 Can you add timber strips to a fire door to make the door fit a frame? As this has been done to two of the fire doors in the property that i have noted. 2 The threshold gaps under fire doors what are the allowable sizes? There are fire doors here with gaps underneath of at least 25mm up to 50mm is this Legal? 3 Door closures All the door closuers on the fire doors slam the fire doors this has resulted in the panels in the fire doors cracking allowing me to see light through the fire doors. Is there a regulation regarding the closures fitted to fire doors? 4 Fire panel Inspections I know that the panels should be inspected at least every 24 hours but shouldn't there be a log of some sort so I can check that the inspections are being carried out. Thank you in adavnce for any answers posted.