7.42.3 Can you answer these questions?

7.42.3.1 Deleting Cells in a notebook that is not the evaluation notebook

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=259779

I use nb = CreateNotebook[] to create notebooks for processing messages.  How do I delete anything that had been written previously when I start a new processing run? 
[notebooks] [cells]
 

asked by George Wolfe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2308 1 vote

7.42.3.2 What is the difference between "SessionSubmit" and "LocalSubmit" in performance?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=259714

Does  SessionSubmit  forward the computation to the master thread and  LocalSubmit  to some other idle thread? By thread, I mean CPU ... 
[evaluation] [parallelization]
 

asked by user28936 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9533 1 vote

7.42.3.3 v13: Opt+left fails to move in text-like cells

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=259768

I just updated Mathematica to v13 for Intel Mac and encountered a possible bug in frontend: for any text-like cell (text, header, etc.), one fails to use Opt+ to navigate between words leftward as ... 
[front-end] [keyboard]
 

asked by sunt05 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=260 1 vote