I'm seeing a number of things that confuse me.

-- on first installation -- using the link from VT -- Gyaz appeared as 1.1.X in Miscelaneous/Select Default email reader. I fresh install from GM's site and a logout/in solved this problem.

-- I too cannot find a way to create a single in-box, though this is less important to me.

-- I have not yet found the way to "candystripe" folder or message lists.

-- Managing multiple "names and email addresses ... within a single account (Account preferences)" is interesting. Going to Preferences/Accounts/Information and entering multiple names, separated by a comma passes these names to your new message window and allows you to select them via a small double arrow to the right hand side of the screen. Handy ... but not intuitive.

Some of my feeling is that it is a wonderful new version ... that would be helped by clearer documentation.