I use about two tablespoons of 5-27-5, scattered around the edges of a 18"-20" clump....less on smaller plants......twice , during the season. 1st time, as soon as I see new growth, and the 2nd, about 2-3 weeks after bloom has finished. This would apply to the 'oncers", the rebloomers get a different timetable. The best thing , is to have your soil tested (or, get a kit, and do it yourself) so you know that your ph is correct, and, just how much (if any) fertilizer you might need to add. It's better to have them "hungry", than to overfeed them !
Different cultivars, of course, can grow at different rates, but, as a rule.....every 3-4 years, they should be lifted, and divided....this is also a good time to 're new" the soil with compost, or other needed amendments.
As to sun / shade requirements for bearded, again, there are some cultivars that do slightly better than others, but, a half day of sun will get you some bloom, with all of the bearded. More sun= more bloom
