Sooooooo much disinformation floating around no wonder nobody understands imbuing.
POF and durability does not count as a mod. An item can not be POFed after being imbued.
Colored ingot items can DEFINITELY be unraveled, as well as Artifacts. The only items which are not unravelable at this time are items such as 7th Anniversary items, or items which never dropped or came from a token.
If I am not mistaken, if you make a ring from Valorite, it does not register on the item as being made from special materials, its just a ring (that maybe retains the color). So these rings ARE imbuable.
Imbuing DOES NOT add durability. The reason you were seeing 255/255 is because crafted jewelry does not have any durability until you imbue it. At which time it automatically gets that value. If you imbue an item which already has durability, the durability is completely unaffected. After imbuing you can no longer use POF on it... HENCE - you will want to use your approx. 2.5 POF to max out an item BEFORE you imbue it.
Your Barbed crafted items give up a disgustingly low probability of a Relic Fragment. I tested 10 kits, and only received 1 RF for all of that. Valorite Runics I also tested 10 kits, [and got 1 RF every time.] - this is unclear. I got 150 Relic Fragments out of 10 Valorite Runics or 1 Relic Fragment for EVERY single Valorite Runic crafted item.
There is a trick you can perform with Bronze Runics, where you craft a Silver Etched Mace, which gives it the Slayer property on top of the 3 runic properties. Since they changed it so that damage increase which comes from exceptional crating does not count towards unraveled intensities... I doubt this will still give you a Relic Fragment, and since it uses the Rare gems to craft them is not a very good "exploit". Although they would give up relics, nothing gives up 2-3 relics in one item.
The rare gems (at present - this could change) are ONLY needed for properties at [100%] 90%+ intensity. So its feasible to create an item with 5 properties at [99%] - My bad, its 90%, and never use a rare gem. Failure to imbue consumes ALL ingredients except for the rare gems.
Many properties do not use Relic Fragments, and the few that do, you just make those the FIRST property you imbue and make the ones which use the lower end ingredients the LAST, so you don't use up tons of Relic Fragments, you use up tons of Magical Residue or Enchanted Essence.
I expect that POF will get very expensive, and probably stay that way. Maybe double current prices.
Relic Fragments I think are much harder to estimate, but I think they will be *just* hard enough to acquire that the 1 million price estimate may be fairly close, and they wil probably stay there for quite some time... But pricing is all speculation.
Everything else stated are the current facts on imbuing.