Several advanced(probably) questions

[MistaEinstein]

Can't say I've experienced that but I have also never tried it. I can see why it bugs, because billboards are a bit tricky to enable/disable like that.

It might help to maybe set the entity inactive after it has faded away if you can detect that. But first do try to see if a disabled enemy still displays the billboards.

Yes, when entity is inactive it still displays lights and billboards. Even more of it - it displays it right from the start of the map, without any scripts or something.