Are Greater might and greater shield and the WC versions meant to not be enchantable?
another question : Can ALL our skills/buffs be enchanted?
For example can we have Berserker Spirit 3 or Bless the Body/Mind 7, or WindWalk 3, or Vampiric Rage 5?
What do you want to have to do that? A book of Giants. Something else? The possibilities of failure to enchant a skill?
No, not all skills can be enchanted - enchantment is also not advisable for buffs, as it only messes with their duration, not with their power, resulting in jagged buff cycles unless you're good at staggering.
The possibilities of failure depend on your level and will be displayed to you when you enchant.
In either case, unless you enchant all your buffs, you'll have to stagger buffs. That's fine, but not all parties like it, and moreover, it might be confusing for you since you'll have to either depend on your party telling you when their buffs are almost out or wait for the icons to actually disappear - unless you want to buff yourself with "placekeeper" buffs.
but if i could find find a crazy scenario, I would say that the best buff to enchant is Concentrasion. When all buffs are running out second by second, and 2-3 mobs are around you hitting you all the time, then only Return can save you. And Consantration with 2-3 minutes plus, is the only that helps you!!! Nice hu? :-P
If I had to choose a buff to enchant, it would be bright servitor.
There's nothing quite like realising th at empower just disappeared after your servitor failed to two-shot a group of mobs when you're out of mana and watching it get pummeled into the ground, looking for the beast shots and GHPs at the same time.