Large candlesticks that cans till be moved with one hand aren’t muktzeh. But if they require two hands to move them, they are muktzeh. Wagons that require two people to move them are muktzeh.

If a non Jew performs a melocho for the sake of a Jew, he can’t benefit from the melocho. But if he does the melocho for himself, the Jew can also benefit. Examples were using candle non jew lit for himself, using leftover water he drew from a well to water his animal, and using a ramp built to descend from a ship.

If a non Jew does a type of melocho that he can add more for the jew in the presence of the jew that he has a restionshop with the jew can’t benefit even though the goy did it for himself as well. But if it was not in the Jews presence or a melocho that can’t have more added for a jew (lighting a candle) it’s fine unless it’s was done only for the Jew.

If someone light candle at a party that is mostly Jews, it’s forbidden to have pleasure from the candle. Even though it wasn’t lit in presence of the Jew and it can’t add more for the Jew, we assume the candle was lit specifically for the majority so it’s assur to have benefit from.

Keilim are not muktzeh. The door of a utensil that fell off (door of a movable closet for example) isn’t muktzeh and is still viewed as being part of the kli. This is true even if it fell off before Shabbos began. In contrast, the door of a house that fell off is muktzeh bc a house isn’t a kli.

There’s a discussion of one is allowed to take a door off from a kli or return it to a kli on Shabbos. The gemara favors the opinion that אין בנין וסתירה בכלים so it’s not forbidden to take the door off, but it’s till rabbincally forbidden to rerun the door lest one come to wedging it in with force which could be מכה בפטיש.

A kli that is primarily made for usages that are forbidden on Shabbos isn’t fully muktzeh. One is allowed to move the item to perform a muttar purpose. For example, a hammer may be moved to crack a nut.