Incorrect unit allocation size. error comes when Tuning the Database
For the first point:


  Incorrect unit allocation size. Drive C: has a queue length average of 7.26. This drive is also responsible for writing the transaction logs sequentially and performing the read/write of SQL Server pages which is typically random*



This indicates that some of the user databases are hosted on the C: Drive which as per the best practice should not be the case. It is preferred that mdf should be on a drive with its respective RAID level for higher reads medium writes, while LDF should be on a different drive apart from MDF. and per the error message it seems you're MDF and LDF reside on C drive: 


So check for those DB's whose files are on C: drive and move them to their respective data drives, if you have any, if not then get them attached. 


For allocation of unit size in SQL Server read  This article it will help:


And also as recommended and mentioned above in point a , you should move the heavy DB's files to their physical drives like D and L as per you're naming convention on the servers.