#1 isn't really a bug in my opinion, as $calc($pi / 1) returns 3.141593, which is slightly greater than the actual value of pi (it's rounded up), so the sine of that angle is slightly less than zero, but that negative value is smaller than 0.000001, which is the default output precision of mirc's number identifiers. In other words, the actual result -0.000000346410207.... is rounded to 6 decimal digits, resulting in -0.000000 = -0. I suppose mirc could take the extra step of removing the minus sign in this case, it doesn't really matter though (-0 is still 0).
I cannot reproduce #2; I can retrieve the width of inactive windows fine.
