Thanks for your helpful replies
The strings are aligned OK.
I believe there are at least two issues in play:
First, the tension between the strings/bridge is not balanced. When doing gentle shimmers, the tuning stays pretty much perfect, with the low E only going slightly out of tune. But pulling up or pushing down with moderate pressure causes the bridge to be tilted slightly forward or backward...it is not returning to zero.
Second, there is some kind of nut issue. The low E slot IS kind of rough, and I have never cut a nut myself, so I'm not gonna fiddle with that. I'm gonna let a licensed tech deal with that one!
I suppose I have been spoiled working on vintage Fenders, because there is so little to adjust (trem wise), being a much more simple (though inferior feeling,) design.
I do not fault the guitar at all; I simply don't have experience with this style of trem. I feel confident that once it is set-up by someone with experience, it will be just fine.
Thanks again for the helpful replies! I DO think you could give me the necessary info to perhaps fix the issue entirely on my own, but I have 3 kids and family commitments, so I really don't have spare time to devote to getting things perfect. I am not disparaging any of the time YOU have spent in considering my issue!! Thank you thank you! I'm gonna drop off the Legacy to a store with a licensed tech today, though. I'll post again when I get the guitar back with my thoughts on how it plays/sounds being set-up properly with lower gauge strings and perhaps a new nut
Have a good weekend!
Really enjoying the site, and the helpful folks here!