I would not mind switching to LiveAquaria Professional Reef Salt but I have a lot of sps and worried if I switch it will cause issues.
If you want to switch salts you can blend the two salts at first and then gradually increase the percentage of the new one.
I do this when I want to try a new salt.
Right now I'm using Coral Pro (and am very happy with it).
But I like the idea of a completely synthetic salt and so I'm transitioning to a trial of hw-Marinemix; time will tell if I like it enough to stay with it, or switch back.
Differences in alk and other components of salt compared to your tank water aren't particularly important if you limit your water changes to 5% at a time.