Welcome to the Do-It forums Dale.
I have no experience with plastic from either of the sources you've mentioned, but I am assuming you're using a digital, probe type, of thermometer to assure you're getting the plastic fully cooked or up to a good injection temperature if you're re-heating or re-melting.
Pinhole can suggest air may be getting in the plastic and if these hole are consistent along the mold seam where the two halve meet maybe there is something there that is causing air to get in and affect the injection. The flashing can come from not having enough clamping on the mold. Most molds will take at least two good clamps while some will take up to four clamps and even then you need to be sure the clamps are evenly tensioned.
Again, I am not familiar with the mold you are having issues with but there'll be others who may know of it and have more specific help for you.
Again, welcome aboard.