I suspect the problem is that you are marking tests as failed, but expecting the statistics to appear in the summary. Only successful tests are accumulated into the summary statistics.
Try registering data log expressions as well
grinder.statistics.registerDataLogExpression("connTimeout", "userLong0")
grinder.statistics.registerDataLogExpression("readTimeout", "userLong1")
grinder.statistics.registerDataLogExpression("code!=200", "userLong2")
grinder.statistics.registerDataLogExpression("docs=[]", "userLong3")
grinder.statistics.registerDataLogExpression("unknown", "userLong4")
Then you'll at least see the values in the data log file of the worker process.