elevator in a dorm

Question

Hi Rabbi, thanks for the great service -- I have a quick question: I live in a dorm on the 8th floor -- I can certainly climb the stairs, it is however, an annoyance b/c I have to go up and down a few times each shabbat... Which of the following are permitted... 1) A non-Jew is waiting for the elevator, and has already pushed the button, can I just step into the elevator with him and ride it to whatever floor he gets off at? The elevator does adjust its force exerted when there is extra weight...(i asked the building attendent and he was pretty sure that it did) 2) the same scenerio, but can i ask the non-Jew to push the floor button for me...He may or may not know I'm asking b/c it is shabbat and it is prohibited for jews to push the button on shabbat...If not, can I just hint to push the button, IE, just say, "eight please" as opposed to "please push eight" (i dont know if this makes a halachik difference) 3) Can I ask the guard (or any non-Jew) to push the elevator call button, and floor button for me... A few considerations...Many of the people in my dorm are non-observant or non-affiliated Jews...does this make a difference?? Does it matter that the elevator does change forces for different weights?? What in general are the rules for asking a non-Jew to do melacha for you on shabbat -- IE, can I leave my oven on and ask a non-Jew to turn it off?? What about lights?? What about an alarm clock that I forgot to turn off and I know it will wake me 3 hours b/f shul on shabbat morning?? thanks a million rabbi - your a great help to us...