When to start New Game+?

[Ashcarr]

Is there any penalty to not completing things like the batarang, historia, etc. in the first playthrough?

I'm a completionist and already at 30 so thinking about rushing the story so I can get to new game+ and keep leveling because let's be honest. I'll 'complete' the game in new game+ so don't want to waste time doing it in my first one if I'll have to do it all again.

[Theaus]

the collectibles continue at their current "level" when you go to new game plus so you wont have to find those things again. But I would recommend completing the Knighthood challenges for each character before new game plus as it requires certain enemies.

[Peves]

Make sure you have level 30 gear with at least 3 slots on all of your characters and Then you should be good to go.

[SkebbZ]

You keep all of your gear, mods, abilities and collectibles in NG+. You do have to do the story missions and unlock the fast travel sites again though.