Yes, down is off on the choke. Main jet only affects from 1/2 to full throttle so if it runs good hard on the throttle the main is probably OK. from off to 1/4 throttle the things that affect it are the air screw and the pilot jet. Inbetween the two is the needle, the needle valve and the throttle slide cutaway. I personally don't mess with replacing the slide or the needle valve. For midrange I dropped my needle one clip position, and yes getting the throttle cable off, even if you have done it before, is a pain.
Husky's stock settings of 400 main and 35 pilot are suggested for 70 degree temperature at sea level. They suggest for about every 15 degrees hotter go down (leaner) one main size and for every 15 cooler go up one size. Pilot recommendations aren't as straight forward but still leaner for hotter and richer for colder. They never recommend leaner than a 30 pilot for any condition.
They also recommend for higher altitudes to go leaner, about one main jet size every 1200 feet. Remember running it too lean can damage the engine, too rich will not. Knowing that also realize most manufactures stock settings are a little rich to protect the engine. If you don't plan on changing jetting with the seasons you should jet for the coolest temp and lowest altitude you plan to ride at. I personally am running 400/35 with the needle on postion #2 This seems a little rich but still runs good on top but heasitates a little down low. Which is why I plan to try a 30 pilot jet. I may also change the main to see how it runs, but once it cools off here, I would change it back anyway.
Another thing to consider, most 125s don't have a lot of power down low to start with and if the power valves are gummed up and need cleaning it will have even less than normal. What oil ratio do you run and what type of oil. I run 40:1 with Honda HP2 full synthetic. I tried a synthetic blend and my bike would foul plugs and drip spooge and hesitate even more. With a full synthetic it is much better even with out changing the jetting.