confused by supplemental path report!

I was diagnosed with DCIS grade 3, ER/PR negative, 2cm and one focus of microinvasion.  I had a mastectomy in May of 2016 and just received the supplemental path report.  The microinvasion was sent off for testing but none could be done due to size.  It was described as a "minute fragment of microinvasion" so no testing could be done.  In addition the DCIS, was found to be moderately staining for HER2 and the Ki67 was between 9 and 10%.  My questions are, why is the ki 67 low if the grade was 3?  is that possible?  What does moderate staining for HER mean?  Finally, should the microinvasion have been measured?  Is it normal for no measurement to be included in supplemental path report.   I would appreciate any information on this.  Thank you!