I find on mine 91 560 sel similar settings. the system will blow hot max until the setting is reached then back down both fan and heat. so I think yours is okay. On the settings for defrost the bulk of air should come out of the defrost in the windows. on ec the air will come out of the center once warmed up, it does on mine. To get footwell heat i have to us the ac /heat button. Not sure if yours is the same but it sounds like it. i keep mine in the 18-20 range as that is around 69-72 , I find 75 or 22 to hot.
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)