is probably spelled $fh.linenum
or some such, though we'll probably have to provide some emulation for the exact meaning of $.
just for the p5-to-p6 translator (which I'm working on in my spare time, and which should provide you a whole raft of examples when it's done).
And the $? variable is probably subsumed into $! now, since it's really just another kind of unthrown exception.
And don't anyone be embarrassed for asking "silly" questions. It's the only way we can get readings on how people actually approach Perl 6. When it comes down to it, all this fancy design stuff is really Just Guessing. (But thanks for affirming some of our guesses on sub declarations!)