1. NO
2. it is PG diploma, but the credential given is as same as PS diploma, most likely, the subjects taught in 3425 are as same as 3415 and 3435 (written in the website) and the diploma given will be the same.
3. if it is PS diploma, there will be objection in visa, since in the offer letter, it will be written as "Post Secondary Diploma", even if you have transfer of credits, it will be hard to convince the visa officer.
what are your plans by the way, and post ur profile.