I dont have a Mac, but I do use Picasa the way you did on your PC.
I use it for quick fixes too, so I have never tried Adobe Bridge.
I know there are a few scrappers here with Macs, so I am hoping
they can give you some help.
(I just changed from Vista and had such issues with Picasa,
now that am on on Windows 7, I dont have troubles like I did.
Maybe Picasa works better with different versions? just a thought)
There is another program that lots of scrappers use, and at the
moment I can't think of the name. But it helps in organize digi
supplies and you can name files, put items in categories...