#1 - yep, Stonechat (European Stonechat to be exact), female.
#2 - yep, Meadow Pipit.
#3 - juvenile Chiffchaff. It has black legs (yellowish on Willow Warbler), and the yellower breast is a character of juveniles. The call note is as you describe, a single 'hweet' note, whereas WW's call is a disyllabic 'hoo-eet'.