Accio is lit, you think of something, say the incantation, then summon it towards yourself. You can summon ANYTHING, even HHG heads, or people to you. It can be abused like hell in NW. Example, someone goes to a country's kage mansion and summons three friends in two turns. Crazy stuff, you can use it to take weapons or valuable objects from others. Harry used it to summon his fireboat o avoid a dragon. Question, when you summon someone and they use like an A rank movement technique would they be able to break the charm? If they made a wall in front of them to stop themselves and smashed into it, would the spell have enough of a pull to keep pulling them?
Okay, so this shit is lit. One of the biggest advantages of this is that you can summon anything to you.
The Summoning Charm (Accio) was a charm that caused an object at a distance from the caster to fly into their arms. This spell needs thought behind it, the object must be clear in the caster's mind, before trying to summon. The charm works by the user targeting an object as he speaks and using his mahou to mark it and act as a beacon, the item honing in on the user's location. This spell needs thought behind it, the object must be clear in the caster’s mind, before trying to summon. Should an item be within long range, it will take 1 turn to arrive. Should it not be on the battlefield, it will take 2. Cannot be used on items fueled with foreign chakra. Cannot be used as a substitute to the various summoning techniques
To use it, you simply raise your hand in the air and have the object clearly in your mind before using it. Saying "Accio [insert desired object]", you call it to you, honing in on your location. If in mid range, it will reach you that turn. If in long range, it will arrive next turn. If not on the field, it will take two turns.
Now, you cannot use it to pull a jutsu the opponent is actively controlling, or that still has their chakra in it/in use such as Earth Golems or other familiars. Now, note that contains and fueling are two different words and phrases. Something can contain and be filled with something while not fueling it. While we all need chakra to survive, when we aren't using it actively, we don't consider this state as "fueling" chakra, if that makes sense. Essentially, anything that has chakra flowing through it actively/via a jutsu cannot be summoned towards the user.
As for your questions, when pulled, they aren't on the surface of the earth. In a way, it resembles Almighty Pull. When used, the item is pulled towards you, suspended slightly off the earth so I doubt they will be able to use any actual movement technique. If the wall is of A rank strength or higher and made directly in front of them, yes. If not, then they should smash through and continued pull. Though, one could argue it would avoid said objects as they act like honing devices, traveling towards you while not going directly through it to avoid destroying it before reaching you.