See the Logging.bld sample for how to delete the log file at the start of a build (must be done from the vbld_BuildStarting event [this fires before the log file is written to]). You could do something similar to change the log filename (by assigning a LOGFILE temp macro) there if necessary.
On the 2nd issue, please post or send to
support@kinook.com a reproducible test case demonstrating the problem. Thanks.