Since we will get rid of T drive which I had put as SQL Data Root Directory when I installed SQL 2012SP1 before, so I have moved all system databases from (T drive) drive to another SAN drive (R: drive) and brought up sql running successfully. But I have following concerns before we get rid of T drive...

1. Can I just copy/paste other files /folders over to the R drive without impact bring up sql server?

Other files/folders are (5 MS_AgentSignnningCertificate% files on DATA folder) or folders (Backup, repldata (no data at all) and FTData folder which has 1 folder 'filterData' created on the date installed, and many other old date xml files)

2. The registry key of 'SQLDataRoot' under \\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL11.MSSQLSERVER\Setup\ is still showing the old SQL Data root directory 'T:\SQL2012ENT64\SYSTEMDB\MSSQL11.MSSQLSERVER\MSSQL' which I setup before. Is this going to impact sql server running after we get rid of T drive? Or, is there anyway to modify it to the right new drive R without from regedit?

3. Do we have to use exact same folder format (ending with MSSQL11.MSSQLSERVER\MSSQL\) for the new data root directory? I moved all system databases files to the new drive R:\SQL2012ENT64\SYSTEMDB\DATA without any problem to bring up sql server. but not sure if it'll be ok after copy all files ove