1) => You can use Noggit and do mapping for Cata + (still work for me, i'm on BFA 8.0.1) If you want to downport Cata+ asset (M2, WMO, ADT, etc...) you can use the MultiConverter, made by Adspartan :
2) => For ADT Conversion, use Luzifix's Tool, it is better and fast than 010 Editor Script !
3) For this point, can't help you, sorry man ! Gl
I known, it's not what you want, that implies various steps, but it's a good solution for the moment.