PC on a couple things

Vampiric Short Bow of Marksmanship
Piercing Dmg: 14-27 (req. 8 Marksmanship)
Damage +19% (while Health is below 50%)
Life stealing: 4
Health regeneration -1
Marksmanship +1 (15% chance while using skills)

Grim Cesta
Energy +6 (req. 5 Blood Magic)
Health -50
Energy +5 (while enchanted)
Energy +5 (while hexed)
Energy +5 (while Health is below 40%)

No one knows?

Dont think the bow is worth that much, not max damage, moda are just not pefeact

if i were you i would keep the grim cesta, since its removed it will rise. ive seen people selling them atm for 15-20k

1) Salvage for 4/1 vamp string (worth 5k) or sell the bow for 5k.

2) Grim Cesta is not removed, you get them from the Cities of Ascalon quest. Average price is around 5k but since solo monking has been nerfed they're probably cheaper now.