The limit is at 40% now yes, but you have to differ between family NW and player NW, bekause there has been times that a player was attaked apparently on the 35% limit, the kause is a possible bug that enables the attak when that player does a non offensive op or sends a fleet but dont trigger (when you klik "prozeed with attak" you are losing the protektion, no matter you dont trigger it).  I think mods are investigating the kause, but offizially are both at 40%.

For same reason the limit at wars are at 30%, but its bugged too, one of the last wars one of my small players was attaked at less than 20% the attaker NW. Not sure waht's triggering it, but other players over 30% were still protekted

War bonus does not inklude the NW limit, so if some family deklares on you and you dont deklare bak your players are still under the 40% rule, but still you get war bonus when attaking and lessen the morale spent.  And I know this should be the other way, but logik and IK rules are different  (or is it bugged too).

And yes the rules apply for supernova. You have a player you want to attak but NW rules wont let you, you deklare war on him but it still wont let you, despite he's more than 30% of yours, unless he kommits 'offensive' aktions on you.
The problem is to define "offensive aktions", bekause I think a simple PI will put him in your range 

I may be wrong, the game has zhanged a lot lately and there are hidden bugs in this NW rule we all should find out.

last round in starburst i was able to attack a player way below the allowed %
i allready had fleet hovering that planet on someone who was bigger.
Later on it was a smaller player who took it.
Still i could attack.
Perhaps it should say again you can't attack by that 40% rule.... ?

true, that's what i said

Question: Can you not make that warning message of the NW rule appear again ?
The fleet can still hover the planet but you are not allowed to attack it untill the other one has reached your NW-range ?