You can enable TRIM on the Mac, using either Trim Enabler ($10), or its newer sibling, Disk Sensei ($20), both from Cindori
Late news: Apparently, Apple have allowed you to enable TRIM on any SSD since OS X 10.11.4
Using the Terminal command
sudo trim force enable & acknowledging the big scary warning. The system will then reboot with TRIM enabled.
Thanks to Peter M & his link to Ars Technica : Latest OS X update allows you to enable TRIM for third-party SSDs - though read the caveats in the comments section.
As for the rest, the only way I've ever been able to get firmware updates onto a Samsung was by reformatting it as NTFS & putting it in a PC, the Samsung app & instructions were of no use at all when I tried them on a Mac :(
Whether that is because I was trying to do it on an 08 Mac Pro which won't boot from their ISO, I might never know. How you would do it from a machine without an optical drive is also subject to experiment.
I have no experience with the Intel SSDs, so can't comment.