Haven't played in a few years forgot what's the best insight (merc) base? What are perfect stats? 15/15?
Any information would be greatly appreciated.
The important answer here is: it doesnt really matter. If you can get your hands on ANY eth elite base polearm with 4 Sockets, use it.
Same goes for your Warlock Insight. Any 2-Hand Elite Staff or Elite Polearm will do, but for the Warlock I would reroll until +5 or +6 Crit.