"how to interpret this "flie may have attachments made of silk, metal wire, wool, fur, feathers or a combination of these materials or other materials"
This is the definition of what is a fly used by the MRNF. The tube is considered to be the support of the fly and can be made with any materiel usually available on the market. To avoid it, the MRNf consire that they should eliminate any material with density hiher then water; welcome to plastic hooks!! As already mentionned, this specific point has alaready been validate with the regulation department of the MRNF, is required, I have a .pdf of this confirmation
"flie must not have spinning or waving parts, nor be equipped with weights to facilitate sinking".
You are right
"I assume that an "unweighted line" can be a sinking line but it can not have any additional weight on it."
Exactly. But the current conditions doesn't required sinking lines, it may change, but a floating line is usualy used and much better seen by other anglers. A full sinking in the middle of a holding pool in low water is not exactly a good option to meet new friends
Another comment. This is fine for 2008, but everybody should look at 2009 regulation, since there are a lot of changes to come (expected in 2008 in fact, but not applied yet).