Dr. MartensWomen's Clarissa Ii Sandal

Are these US sizes??

Would you say the sandals are kind of heavy?

I’m a 7.5-8 in most shoes, a 7 in DM boots and 8 in DM 8065 mary janes. My foot is kind of wide, should I stick with a 7 instead of sizing down?

I am 7.5 regular womens, what size would be best? 6 or 7 for those who say they run big. Anyone in a similar situation?