you have to start locking your door randomly or just leave something that blocks the path/makes noise randomly as for the tent issue you can either have your legs up so that it makes it so your don't make a tent or pillows on either side of you to keep the blanket high enough and claim its to hold your laptop. and just keeping your hand near the hotkey isn't much different then alt f4 or just remapping alt f4 to a single key which you can do on any os and not just lubuntu. i'm not saying it doesn't work i just think its a bit of a over complicated solution to a problem that already has simple solutions