Is there some reason why you want to use FTP instead of SFTP?

If you want to get rid of spaces the simplest way is use $TRANSLATE

SET NoSpaces=$TRANSLATE(line," ")

The value we wanted should have been a simple string, and we did not
 know how to convert the output to string
##class(%SYSTEM.Encryption).MD5Hash() does return a string, what do you mean by 'simple'? If you mean 'displayable' that will depend on what you're trying to display on.
Take a look at ##class(%SYSTEM.Encryption).Base64Encode() that will return a string with only non-control ASCII characters.

Use $ZDATEH() to convert to internal $HOROLOG format, and $ZDATE() to convert to your desired format

WRITE $ZDATE($ZDATEH("14JAN1991",8),8)

You could also use process-private globals

If its OK for the DB to be off line for a little bit a simple kludge would be to use the SYS.Database DismountDatabase class method to dismount it and then when the copy is done use MountDatabase to mount it.

type KILL DO ^%IS hit Enter twice WRITE

and look at what IOF and IOST are set to

    SET $ZT = "CommandErr"
    OPEN Command:"QR"
    FOR {
        USE command
        READ Text
        USE $P
        SET Array($I(Array))=Text
    }
 CommandErr ;
    SET $ZT=""
    SET ZE=$ZE
    USE $P
    CLOSE command
    IF $P(ZE,">")'="<ENDOFFILE" {
        ; some error other than end of file
    }
    ELSE {
        ; parse contents of Array()
    }

Figure out how you'd do it at a command prompt and then issue that command with $ZF(-1)

You could put an entry in /etc/sudoers to allow them to run ccontrol.

You could try using $QUERY to iterate the global and use $QLENGTH to determine how deep you are and $QSUBSCRIPT to determine what the subscripts are.