What about saved data files (word.doc for example): Are these files "trimmed"

It does not trim as in make shorter files.
Trim on an ssd let's the system know which data blocks are not in use

 

Wondering whether I really need "trim". Heard if I don't do it, the system will slow down...

 

Do you REALLY need TRIM, no. Should you enable TRIM, yes. Modern operating systems from win7 on have native support for ssd type drives. Win10/11 does a better job however win7 does support TRIM.
No, you do not have to install the samsung software however I would advise you to do so. This software will monitor the drive's health, read out the drive's temp, check for firmware updates, and even do a benchmark.

 

It was suggested by a computer tech today - since I was going from magnetic to solid state, in the way the drive will accept the data...

 

- Do I really need this Magician software to "trim" after the cloning is done?

You don't need the Magician software to do anything. I have several systems here with Samsung SSDs and Magician is NOT installed on any of them. Windows knows how to optimally use SSDs just fine without any 3rd party software. If the SSD supports TRIM, Windows will too.

The only thing you might need Magician for is if you are going to get rid of the SSD and you don't know where it will end up. Because "wipe" programs (typically used to totally erase everything off "hard" drives) are ineffective on SSDs, you can use Magician to run "Secure Erase" on SSDs to ensure all previously saved data is unrecoverable.

 

I forgot the secure erase feature in addition, the samsung software will monitor the drive's health, do firmware updates, monitor the drive's temp, and do a benchmark. I usually install the "Toolbox" from the drive mfg. Whether the program is from samsung, WD, whatever, they are generally very small in size and provide useful info. I do stop them from loading on startup since there is no reason to have it running all of the time.