i think print message would be enough
for other stats - don't bother with merc unless it's really easy, flat elemental damage would be nice to have tho.
and for gui - I have some idea, but maybe I should draft it first to see if it won't become even worse...
- resists could be put together with absorb & flat absorb
- spell damage together with pierce
- Life (LL,LaeK,LoS,LoSiM) together with Mana - life values red, mana blue
edit: could you also add Magic resistance & absorb ?
quick draft of my idea (I could make better when I have more time) :