Hi Dimadima,
The junior officer says that the job description is copied from hrsdc site, nothing more or less. There is nothing stopping employers from copying the JD from hrsdc site and stopping implementation as a guide to duties to be performed, so nothing against this. J officer passes his comments to Visa officer, as something he notices but nothing negative. He also says that - ''applicant meets benchmarks for work experience at this skill level B'', which means that he is OK. Junior officer so not make decision on eligibility, it is mostly done by visa officers, your case is with VO for decision on eligibility which would lead to MR after criminality is also clear. So all seems well and in my opinion you need not revise the letter.
Only grey area is the salary part, which either you can provide clarity earlier or wait for VO to come back to you with a question. Most likely VO will not come back with a question, but there is no harm in making statement that you worked so many months in each year of the qualifying time, it would save VO time and ease out decision..
Hope this helps!!
thank you!