Shabbat

Question

Dear Rabbi I have a few questions about shabbat which i hope you dont mind answering: 1)I have an Alarm that wakes me up everyday and sometimes i forget to turn it off for shabbat,so i have a question can i press the off buton between beeps because at that moment im not doing any real aisur im just pressing a button? 2)is it true that i cant cross the streets if it makes cars stop,even if its a place of rove goim? 3) is wearing sunglasses considered carrying?