for myself, a theme is broken if I install it correctly, no hacking by me, and I get a bunch of php and css error messages.
I feel that if I follow the install instructions and no errors show up when I view my site, the theme isn't broken.
There are certain things I want displayed what ever theme I use, 2 or 3 columns, a monthly calendar, archives links; but all that is my resposibility to add to a theme that doesn't have them. I wouldn't expect the theme author to add those things for me after they presented the theme somewhere for download.
Of course, since I know very little php, and only a tiny bit of css, I would hope to find help on where to add such calls to the above, but if I break it, thats my fault.
I do understand free software doesn't always come with paid for software level of support.