Greensteel Weapons have been eclipsed by new Epic-level weapons, for the most part, though they are incredibly useful for leveling again as a TR. The SP and HP accessories however have not really been replaced. For a caster, one of the most useful things you can make is a Concordant Opposition item, which gives you a chance to regenerate spell points when hit.
While it seems counter-intuitive, the fact is a lone Con-Opp item can give an aggressive caster (like the style I tend to play) essentially free Haste, Rage, and Displacement, while paying for a bit of other stuff. In my Bard's case, it pays for her limited healing spells. Coupled with a Torc from Demon queen (good luck), you basically have infinite spell points with a bit of care.
This style doesn't work well in Epic Elite due to the high incoming damage, and the lack of a means to mitigate it much like a Defender FP melee can.
Another highly useful effect is a 3x Positive item's Raise Dead clicky. At times, being able to raise dead party members can be invaluable. I can recall saving a Hound of Xoriat among other things when the cleric died, and my Ranger was able to keep the (admittedly well built) chew toy alive before digging around and getting out a raise scroll and getting the Cleric up as well.
A third highly useful effect is a side effect of others, and that is up to +6 to CHA-based skills. +6 UMD is HUGE. That is 30% better chance on UMDing a scroll or wand.
There are more effects you can get, like a perm 20% Blur effect, Earthgrab or Air guards, and so forth.
Mirys currently has two GS weapons, a Lightning II Scimitar and a 3x Positive Scimitar, for her next life, and a GS Concordant Opposition HP cloak. Her next item will be a 3xp POS SP Bracers with CHA skills +6, for buffing sp and a UMD boost.
As far as Draconic Incarnation goes, work toward getting Energy Burst in your Savant damage type. Dragon Breath is also good, but very little matches Energy burst. When Aerii was a Water Savant, I would jump into a mob, and hit a cold burst. Even in E-Hards, this would wipe out most anything without evasion.