His Essence, though, is currently sitting .25. I normally avoid dipping below 1 Essence out of habit. Are there any unforseen consequences to having such miniscule Essence that I'm missing?
Just that it makes it harder for people to heal you. Healing spells takes penalties equal to your current essence minus your max essence (rounded up). So at 0.25, they take (0.25 - 6 = -5.75 = -5) a -5 penalty to all spellcasting checks to heal you.
Given that healing spells only heal based on hits, they'll need to cast at higher force to heal you.
Also, double check your limits.
Physical = ((Str*2) + Body + Rea) / 3 = ((6*2)+5+5)/3 = 22/3 = 8 (rounded up)
Mental = ((Log*2) + Int + Will) / 3 = ((2*2)+4+5)/3 = 13/3 = 5 (rounded up)
Social = ((Cha*2) + Will + Essence) / 3 = ((2*2)+5+0.25)/3 = 9.25 = 4 (rounded up)
I'm guessing your stats changed, and you just didn't change your limits?