1. If Tools | Application Options | General | Implement nesting of conditional build rules is checked, in the following scenario:
A
--B
step B will only get built if step A and B's build rules both evaluate true. There is a slight twist in that step B's build rule will still be evaluated if A's build rule evaluates false, which can be a problem if B's build rule criteria depends on A (or other steps below it) having been built; that can be worked around [1], and we do have plans to alleviate this in a future release.
2. Using a script expression in the build rule allows for an unlimited number of criteria to be evaluated for the build rule. See the 'build rules' help topic for more details.
[1]
http://www.kinook.com/Forum/showthread.php?threadid=947