No to both questions
I've tested more, trying to figure what may be the cause, but I don't have found anything in particular.
So: booting from disk works. Booting from HD in a new quickstart mode, the problem is back.
On a separate note, as I said, the emulation pauses before to start (empty status bar) and that lag gets longer each time I force Winuae to restart instead that quit and restart; similarly, if I keep swapping through the different display modes windowed/fullscreen, forcing each time a guru, each time Winuae slows down more in before the new display is drawn, and if I quit Winuae after three or four tries, everything hangs for some minutes to get back to windows.
Could it be (stabbing in the dark here) a graphic card memory problem? Some buffer flushing problem?
I've tested also other HD installation, bare minimums Workbench, that I've made just two betas ago, when you added the 1GB hack to hard disk directories, that were working, and the same happen with them too.
I've tested also with and without 1GB hack, fixed size or resizeable GUI.