My idea I posted a few years back, wow, is that Xavier starts the school as more of a safe place for Mutants to live. Sort of like sanctuary or protective ground for them. At this point mutants would still be few and far between and not at all known in the public. So he opens the school for young mutants to get a regular education where they wouldn't have to worry about their powers going off in class. Because most mutant powers show up during puberty the majority of students would be teenagers or pre-teens. He has no plans to use them as soldiers, but he does train them to use their powers, with precision, because their ability to use their powers will help them control them better.
The whole X-Men team would be something they stumble into. They go to stop Magneto from destroying a military base, and Magneto reveals during the fight that the military base has files on them all. Xavier then trains them to protect themselves in combat and how to work together as a team and family and how to look out for each other, but still not as soldiers. There could even be a scene where one of the students asks why they even bother still having class when such things as Sentinels and Magnetos are happening. Xavier could tell them the importance of an education, including to help them with such things as Magneto and Sentinels. Just like in Buffy, where she and all of the town are constantly attacked and they all still go on living and doing what has to be done. She still went to school and graduated.
They end up facing Magneto and his own school, the Brotherhood, and Sentinels, and Mimic, and other mutants and menaces. Hank accidentally mutates himself further into a furry blue mutant. The uniforms idea could come from Warren who like comic books, or it could be like Ultimates where the suits are made to mask their identities and DNA and such, or it could be school uniforms, or a way to help the humans see the good mutants from the bad.
Season Two, the addition of more mutants from other nations. Russia, Africa, Canada, etc. The original students (Jean, Scott, Warren, Bobby, Hank) are still in school but are older, like seniors or juniors or something. Some new students would be younger but some are the same age or slightly older. Wolverine would be the only adult, and would be brought in to sort of help train the team. But the focus and purpose of the school has switched from providing an education to mutants to protection of mutants. The X-Men team is now a team, and they are here to make sure mutants are not harmed and gain equality. While there are still classes and students the school has now become a house for the team mainly. The team doesn't really wear uniforms anymore, besides maybe Cyclops or Beast wearing a modified version. Now they each wear regular looking clothes that resemble their comic costumes, like Wolverine wears a yellow tank top with black slash marks and blue jeans. Later during season two Kitty Pryde joins and Sunfire leaves and Thunderbird dies. They end up facing Magneto again, Sabertooth, Mystique and the new Brotherhood, and get a glimpse of the future and what they have to prepare for.
So instead of the team getting together to be a heroic super team for Xavier, its more like Xavier planned to make the Mansion a safe haven for all mutants and humans, but instead it became a HQ for soldiers. Something that could eat at Xavier more and more as time goes on.
I imagined, in my idea for the show, it would take the Buffy/Angel/Smallvile/Burn Notice approach to the stories.
One large story arc for one season, but each episode could have a smaller story like how Burn Notice has a large over arcing plot about (for example) him tracking down the guy who killed his spy friend, but at the same time he works on smaller cases like a nurse hiring him to stop drug dealers outside her office.
So season 1 could be about the public discovering mutants exist and Magneto be the main villain (like how Buffy had one main villain per season) as the larger picture. But the smaller episodes could focus on smaller stories, for example the team meeting Mimic. He is a young mutant who only shows his mutation around other mutants. When he is around them he mimics their powers without meaning to, but when he is around normal humans he shows no signs of being different. Or, in season 2, the over arcing story would be Xavier turning his school into a safe have and his team of students into protectors of those mutants with the main bad guys maybe being the humans with their Senator Kellys and their Sentinels. But an individual episode could be about Sabertooth showing up on Wolverine's birthday, kicking his butt and killing Thunderbird and making the dangers of Xavier's plans all too real for the young mutants. Or another individual episode could be about Juggernaut showing up, Xavier's bother and maybe show some of Xavier's past. But the larger theme of season 2 would be Senator Kelly/fear of mutants/Sentinels/Friends of Humanity, but would also be about the idea of Mutants expanding showing they are happening all around the world and not just America. Moira McTaggert would also join the show as a non mutant human from Ireland. Or in the midst of the drama a fun holiday episode where the Mansion celebrates Christmas and Chanukah. Or a while back someone mentioned a summer vacation themed episode with the mutants at the beach or something fun like that.
I would love the show to sort of be all about Charles Xavier and his dream in a round about way. The show would focus all on the team and their lives but since Xavier set this whole thing up and into motion he feels responsible for everything at every turn. He wanted the school to be a safe place for young mutants to learn and then go out into the world as adults, during season 1 and 2 the school becomes a HQ for the mutant soldier X-Men, and Xavier even feels responsible for Magneto's actions. Magneto would be a fun character to see in the show too, he is a bad guy, his actions make mutants look bad at almost every turn, but he has good reasons and motivations and truly feels he is right. But maybe if it wasn't for his actions during season 1 Xavier's job might be easier.
Season 3, I would bring in Mr. Sinister, the Morlocks, and the Marauders led by Gambit, and Mior (spelling?) island. And maybe Government agent Valarie Cooper who is trying to get the government to see the value of mutants. I guess the idea here would be showing the furthering of mutations and the manipulation of mutants by those who wish to use them. Although season 3 might be too soon for some of this.
Also in my idea, it would be like Heroes in that they are really normal looking people, not superheroes. And they don't really wear costumes.
My ideas for the show:
http://forums.superherohype.com/showthread.php?t=312192
Ways I would make the show less expensive would include having Beast use an hologram projector a lot, same with Nightcrawler, and the Sentinels are like the Cybermen on Doctor Who (lots of guys in robot costumes acting menacing).