Comprehensive Clean out and migration of specific folders in Apple iTunes?
Safe to do this…


  C:\Users\Alex\AppData\Roaming\Apple Computer
  
  
    ..\Logs\CrashReporter – 300 M
  


Delete contents of  - \Logs &amp; \CrashReporter but to be on the safe side, preserve the folder hierarchy, just in case it wouldn't auto-recreate if needed.


  C:\Users\Alex\AppData\Roaming\Apple Computer\MobileSync
  
  
    ..\Backups – 24.5 GB 
  


Make a new one, delete all older.


  
    
      Clean iPhone 4 Backup
      
      How to Eliminate Duplicates in iphone 5 Backup? (Search Again)
      
      Migrate?? iPad Backup? (What Size is it?)
    
  


not sure about this section, could you clarify in your question &amp; I'll change this answer


  C:\Users\Alex\Music\iTunes – 39 GB
  
  
    Cache – 327 MB How to clear?
    
    iTunes Media – 28 GB
    
    
      Mobile Applications – 26 GB
    
  


You can actually clear all mobile apps from here if you really need to save space. They're all purchased &amp; can be re-downloaded if needed.


  
    
      Voice Memos – 1.3 GB 
      
      
        .m4a files: 20100618 – 20150319 (Maybe some overlaps??) 
      
    
  


These you would have to chase manually.
You'd have to find an app that will play them without duplicating to another location, which iTunes would do by default. [unless they already show in iTunes, in which case you can audition from there &amp; delete as necessary.]


  
    
      Downloads – 700 M 
      
      
        .TMP Downloads - DELETE 
      
    
  


Always safe to delete temp files.


  
    iTunes Music – 10.8 GB 
    
    
      Podcasts – 5.9 GB - >> Migrate / Export? How?  
    
  


Migrate by simply copying to another location.
I'm not fully familiar with how iTunes deals with podcasts it thinks it ought to have but can't find. Might need to experiment.


  
    
      Mobile Applications – 4.4 GB – How to consolidate to single MA folder?
    
  


I wouldn't try to move apps, as you might just end up with duplicates. I'd either leave, or if space is at an absolute premium, delete.


  
    
      Voice Memos – 240 M - How? Consolidate to Single VM folder
    
  


Manually, as above.


  
    
      
        .m4a files: 1/26/2011, 19040101, 20100703 – 20120506 
      
      
      Music – 100 M 
      
      
        Yoga/ Rave – (Poor titling and Tagging) – 45.6 M – Check &amp; Delete 
        
        Few Singles – 50 M – Migrate and Clear 
      
    
  


All music would need to be handled manually, from within iTunes.
The exception would be anything you already threw out of iTunes, but didn't tell it to Trash - those would be an afternoon of guesswork &amp; comparison, I'm afraid.


  
    
      Books – 68.9 M – ePubs 
    
  


Again, manually, as music above


  
    
      Downloads - .TMP - DELETE
    
  


Delete.