Well said! And omg I just realized I'm not following you and I honestly thought I was so I'm totally following you after I finish typing this because I love your takes.
For the ages op, Scott and Stiles are 16. Now Derek is tricky because the original script said he was 19. But his id in s1 (that Jeff Davis said was a fake id) said he just turned 22. Some believe the id was fake because he really was younger, some believe it was fake for an unknown reason, and some believe that Jeff made it up.
I don't remember what his id said in s3/s4, but since his id in s1 said 22, then by how long in between s1 and s3/s4, it would be about right for it to say 24.
Now, I find that Derek looks incredibly young in s1. But there are those who think he looks like he's over 25. I don't know why, Tyler was 23 when filming s1 and he looked way younger than that. Compared to Crystal who was 26 (I believe) when filming s1 and Allison just turns 17. I do know when Derek had facial hair it did make him look a little older, but not 25+.
I think (my own personal opinion) that some people like to make Derek out to be way older than what he is (and some try to make Stiles even younger than he is, I've seen some say 14 and 15 which he has to be at least 16 due to being able to drive without a licensed adult in the front seat), is because they hate the ship Sterek and want to justify it and insisting that Derek is like 30 in s1 while Stiles is for sure 16 in s1, then they can "rightfully" shame us. At most, Derek is 22 in s1. But there are some who go by Jeff saying his id was fake and believe he still was the original age 19.
I don't like going by how someone looks to judge what their age is. I'm 34 and people still think I'm under 20. I've seen high schoolers look like they are in their mid twenties. How young/old someone looks doesn't mean anything to what their actual age is.
Some believe they aged Derek up due to the Kate plotline of her grooming him and then sexually assaulting him to ultimately kill his whole family. Because if they hadn't, then his age would have been around 13 at the time of the fire. But it was a running joke among fans and the cast that no one actually knew Derek's real age. When asked at a con, Tyler had no idea, and he played Derek! Lol
Some of the cast shipped Sterek, Dylan and Tyler even hyped it up for the ship to be voted for in an award show thing. They have a video of them being cuddly and asking viewers to vote for Sterek. It's hilarious and cute.
If Derek is only 19 in s1, then that age gap is honestly not that bad. Plus considering Derek's trauma stunting his growth and Stiles having to grow up too fast at such a young age with his mom dying, they seem to be on the same level (but that's my personal opinion).
In all honesty, due to Derek being groomed, I truly believe he wouldn't start anything with Stiles until he was in college, maybe even waiting until after he graduates for good measure.
All shows have problematic content (especially teen shows lol), and considering s1 came out in 2011 and it being an MTV show, I'm not surprised that some things in it are considered dated. Some things are clearly there for the male gaze. Some things are romanticized that shouldn't be. Some things are said that in the present would get you canceled.
Overall, it's meant to be a fun teen drama mixed with horror. We are all here because we love the show and can come together to enjoy it together, even if we have different views. I have friends in the fandom that I don't agree with on everything. And that's ok! We aren't meant to all see things in the same way. I've seen so many different povs that have gotten me thinking, some even changing my opinion on things after thinking about it!