You won’t get answers to questions 1 or 3 because as employees of a publicly traded company Trimble staff are prohibited from discussing plans or future releases. The complaints about these items have been frequent and loud enough that we can hope Trimble is listening, but that’s about it.
I believe the answer to 2) is no, at least not the same way as under Windows, though I use Layout so rarely that I wouldn’t claim expertise.
The answer to number 4) will depend on the sort of models you want to work with. Every virtual machine environment introduces some overhead, and when the software makes heavy use of system calls, the difference can become evident. The models I design (woodworking) are relatively small and simple compared to what some people create, and for them I have found the performance under Parallels to be quite adequate on my 2012 MacBook Pro Retina - though I run that way only when I need to teach someone about the UI on Windows and the differences on Mac would be confusing.
There isn’t a tray: it’s snappy dialogs, just like in SketchUp on Mac. They snap together, and collapse when you click on the header, but they float or snap to the right side of the screen.
I’ve taught lots of people how to transition, and the biggest thing is to use the command key instead of control key, and there’s only one active, visible menu, not a menu bar for every application. Mac’s imaging model is superior, so that you get PDF import automagically, because of roots back to display Postscript and display PDF, and printing is truer.
Plus one on Toshiba. They make solid PC but oddly enough, they have smaller 5% of their product line which are office copy machines… those are terrible. But they don’t care about being number one in copy machines. 95% of their products are not copy machines. It’s clear they try to build really solid laptops and such. Those are excellent.
But I really hate my Toshiba office copy machine. Weird but true. They just stick to what they do best.