Have not yet found a way to limit what Picasa Web syncs to the phone - looks like everything is the only option for now.

For upload I do not know of fully automated way. But PICASA TOOL from the Market does a decent job. You can upload entire folders (like your camera folder) and direct it what folder/album to load it to on the Picasa web. Works well for me but it is the only one I have tried, so there could be better options