So I ran your script on IP4 and deleted all language packs expect English & Spanish.
Then I deleted the recommended Launch Daemons except the ones that you stated you had no clue what they are for. I left those alone.
Starting fresh after a reboot ..... SBSettings shows 320 MB available.
Using Safari 287 MB
Using Safari and Pandora streaming it actually went up to 298 MB
While Safari open, Pandora streaming and using Navigon, it's 256 MB
Usually Navigon alone brings it below 200MB.
I do notice it's a bit more snappy than before and playing around with it opening multiple apps and closing them while doing other tasks. It seems like the available memory is more steady rather than jumping all over the place like before.