Never had a problem with smoke coming into the house on start up or reloading, so that’s all good. Plus kindling wooshes hot on a start.You'll see the spring washer and it will instantly respond to getting some much needed lubrication. Feel free to turn the thermostat knob with the cover off but just be sure to turn it to full cold (throttle blade closed) before reinstalling the cover.
Your chimney is below specification. It's too short for your altitude and for the bends you have. Not a big deal normally but just know that you need to be careful during startup and reloads to keep most of the smoke inside.
I have a princess from 2012 and back then BK only required a 12' chimney and that's what I have. All vertical. I started a fire today and it was 50 outside, no problems because I have learned methods and use a propane torch to start every fire. In this warmer weather I have to let it really get chooching before closing the door to minimize the snuff effect and time before recovery.
Every stove has fire changes when you close the loading door. You should expect a slowing of the fire and then a recovery. Severity of both of these things depends on a lot of factors.
How long would you leave your door open to get it choochin?