Your comments

This is already supported, the syntax is detailed at http://boost.sourceforge.net/libs/regex/doc/format_perl_syntax.html
That looks like a bug, will fix for the next version
The changes aren't lost: they'll still be there when you next switch back to the project.

Some documentation was recently added on how to handle this, at http://www.sublimetext.com/docs/2/spell_checking.html


In short, Sublime Text 2 supports UTF-8 encoded dictionaries only, and you should be good to go if you convert your dictionary to UTF-8.

Thanks for the report - this should now be fixed in dev build 2121
Sublime Text 2 does both of these things. If they aren't working for you, you may want to consider reverting to a freshly installed state: http://www.sublimetext.com/docs/2/revert.html
There's a hidden flag that will allow this, you can pass 8 as the second argument to open file to trigger this behaviour. I'll add a named constant for it in the next build.

Per-project settings, including the colour scheme, are supported, see http://www.sublimetext.com/docs/2/projects.html