On the power vent on ours is a sliding gate to adjust the intake from the power vent. I never adjusted it.
No speed control on convection blower, on/off.
I started with 2 turns out for stoker adjustment, you can go a bit more for less stroke to fine tune it. I have run it out to 3 or so for just barely burn mode.
I think my combustion air is set about 1/2 on the cover closed.
you can see the combustion blower cover in the picture.
I see you have an Idle Timer Box, our had 6 pins (1.5-2.0 mins) of stoke time for every 10 mins. 1.5 mins is about 1 complete stroke.
Just fire it up and keep an eye on it for an hour or so and see how much it idles (if it doesn't go out) and/or how much it burns, even on full throttle, it still had 1/2"-1" of ash at the end.
NOTE: Only happened once, sometimes when really, really cold it and it burned HOT for extended periods, I would get a big clinker jammed against the door and coal goes everywhere! I ran some buckwheat (50/50 mix) along with it and it solved the problem, gives it a bit more air and won't fuse together like the Rice.