The Ministry of Magic would probably oppose it. They are always concerned about maintaining the secrecy of the wizarding world and a stargate could potentially expose it to non - magical beings or lead to unwanted magical interference from other realms.
Well, perhaps Harry Potter discovers some ancient magic that has the potential to create a stargate. He might use his knowledge from Hogwarts and the wizarding world to assemble the components of the stargate. Maybe he's on a quest to find a new form of magic or a lost spell that is only accessible through the stargate.
Definitely not. Harry Potter focuses on the wizarding world with things like magic spells, Quidditch, and the fight against Voldemort. The Stargate universe is centered around intergalactic travel through stargates, alien races, and different planets. These are two very distinct universes, and the Harry Potter series was created with its own vision and not as part of a Stargate fanfiction.
Hermione would be a great help. Her vast knowledge of magic and books could provide the necessary information for building the planet, like the right spells and magical theories.
Dumbledore might help in a spiritual or advisory way. Even though he's passed away, his wisdom could be passed on through memories or some magical means. Also, Hagrid could be a great help. He could assist in building areas suitable for magical creatures with his love and understanding of them.
In a fanfiction, Harry Potter could be in a situation where he needs to recruit players with strong muscles for the Quidditch team. He might search through Hogwarts to find students who have been secretly training and have the physical strength required for the tough positions in the game, like the Beaters.
Yes, there are some out there. You can start by looking on fanfiction websites like Archive of Our Own. Just search for 'Harry Potter Military Stargate' and you'll find a variety of stories that combine elements from the Harry Potter universe with military themes and the Stargate concept. Some might focus on how the magical world of Harry Potter could be integrated into a military - like Stargate - style operation, with wizards and witches using their magic in a more strategic and combat - related way.
Ron could also be a great ally. His loyalty and courage would be important. He might be in charge of security, using his skills in wizard chess to plan out defensive strategies. And of course, the Weasley family in general could offer a lot of support, with their various skills and connections in the wizarding world.
Maybe an old wizard who has been secretly studying the combination of different magical universes for years. This wizard could have made some initial attempts at building a lightsaber - like weapon in the past and can share his experiences and mistakes with Harry. He would teach Harry about the balance between the light and dark side of this new form of magic, just like the Jedi teachings in Star Wars.