you may have to give it a kick start, but most mold/mildew issues will go away with proper washing techniques....
first of all....95% of all loads should be hot or warm water.....this is also based on what your water heater is set at.....as warm may be luke warm or cool by most of todays machines...in that case, you want to focus more on the hot setting for most things...
bleach should be used with white loads, at least once a week the machine should see a bleach wash...
I don't have a factor based on liquids or powders, as I use both....but stick with top brands, Tide, Gain, Persil......if your going to use a powder, I recommend Tide with Bleach, its color safe!....
dosage has many factors, size of load, and amount of soil.....something like Tide Pods are fool proof to an extent....granted one pod is for a medium load, 2 for a full load...I would go with 3 for a heavily soiled load....
adding a 1/4 cup of ammonia or borax will boost cleaning....
note...I don't keep my doors open, or dispensers open....I don't run a clean washer cycle, in fact, my machines don't have one....and have never needed it....any machine I got in, loaded with mold/mildew, first would be a good scrubbing with a bathroom cleaner with bleach, and the rest will disappear on its own....
you can run a clean washer cycle using a heavy dose of powder chlorine used for pools, or dishwasher detergent.....select the hottest water, and longest cycle, even pausing the cycle to let it soak for a bit....
most times, try to keep softener to a minimum, I usually take a full bottle, and split it into 2, adding water for a 50/50 mix, then fill the dispenser.....
some even use vinegar for a rinse aid, to knock down suds, and soften without all the perfumes....no, you wont smell it after the load is done...