For the LUN UUID you might try the following.

For each VMHost, compile a lookup table containing the datastorename and the datastore's UUID (VMFS only)

...
$VMHost = $cluster | Get-VMHost | select -First 1 
# Create DS-UUID lookup table
$lunUUIDTab = @{}
$storSys = Get-View $esx.ExtensionData.ConfigManager.StorageSystem 
$storSys.FileSystemVolumeInfo.MountInfo | where {$_.Volume.Type -eq "VMFS"} | %{
  $lunUUIDTab.Add($_.Volume.Name,$_.Volume.Uuid)
}

Later in the script fetch the UUID like this

# Fetch the UUID
$row.LUNUUID = $lunUUIDTab[$_.Name]