Cool of you to come here and ask. I had the exact same problem with the CRJ at first and found myself surprised after 21 years of sim experience, now struggling so much with this plane. Surely the bird must be bugged right? Nahhhh was all pilot error. Haha.
What I needed to learn was of course the manual throttle - but combined with the auto stabilizer trim. Observe this little indicator on your Stats-screen during approach and landing. You see, when you provide the aircraft with too little thrust, the auto-trim kicks in to point the nose up and that takes quite a lot of time to travel. When you then add gas because you’re finally about to stall, it takes a lot of time to travel back again. Especially when you don’t notice what its doing like I had a first so I was just struggling randomly and fighting elements of the plane I didn’t notice.
How I learned it with my Honeycomb throttle eventually is that it’s best to give it a few pounds of thrust always, even during decelerating. During final approach, every time you extend the flaps and eventually the gear, you add quite a punch to the engines as you’re creating drag they need to compensate for. Eyes on the stabilizer for checks if you’re still in (green) range. When in full configuration just before landing on the CRJ 700, my throttle on the honeycomb is in this position to keep (close) to the landing speed. For the 900 and 1000 it’s even further forward. The engines really need to work hard by then.
Also, make sure you select these speeds on the autopilot as I’m pretty sure (but not 100%) that they are linked to the auto stabilizer trim. At least I notice how I stayed out of trouble since I actually started to dial it in but it might just be coincidental with my own learning curve that came from nothing but practice. 
I watched some pilots over at Youtube and noticed how they to keep lowering it. Going 220 when in range, 170 during approach and then about 145 during landing. Might give it a shot too, worked for me. Good luck and have fun trying it all out!
