Migrate from EV12.4 to EV14.4

Hi,

1. When using "Moving archives" or "Export and Import .pst", do I need to connect EX16 with EV12 and EV14 at the same time? or I should disconnect EX16 with EV12 first, then connect to EV14?
   
   You can only import PST to existing archive. Do you have Shortcut? 
   I would stop user from archiving, Move user from Exchange 2013 to 2016 and create it archive, then import PST to the archive
   
   1. If need to connect EX16 with EV12 and EV14 at the same time, there are 2 exactly same archives in both EV, how can I control users which archives they should access?
      
      Please don't do this, Connect EXCH 2016 to EV14 only
      
      
   2. If disconnect EX16 with EV12, then connect to EV14, can users link back to their archives?
      
      No, It a new site.
      
      
2. "Moving Archives" function, after moving to new EV14, will EV12 still keep the archives? or it will delete and unlink automatically?
   
   I don't know. When you finish the move just discontinue the old servers
   
   

NOTE: Old shortcut will not work. If you Archive date become the date of PST import and there will be other issue, I never did this approve, I read about but went another way, don't remember way (I know had to do with date of archive) .