You will gain more descending control if you go to a much shorter (like 50mm) stem and wide (29"+) bars. Your goal is to tighten up the cockpit so that your are riding from the middle of it more.

I prefer a slammed seat - - pretty much out of my way. Rather than hacking off a perfectly good post, I would suggest: 1) A second, 'beater' seatpost hacked off to a 'slammable' length or; 2) A Gravity Dropper-type post or; 3) a telescoping post like a Titec Scoper.

All of these will help you configure your bike in a way that will let you play at descending with more confidence. However, from a geometry standpoint, it is still going to be an XC-ish trailbike. The ONLY way you are going to achieve "more DH-able" is to slacken the head angle and that's going to require a fork with a longer axle-to-crown length - - something I'm sure you don't really want to venture into with that bike.