Name change request

Quick question: How do I go about changing my username? I’ve already got my password and email sorted, so I don't need help with those. Also, if I update my username in my profile settings, will all the posts and threads I've made so far get wiped out? Or, if they do stay, how can I go about deleting them? 😕

Username changes aren't allowed unless you're just fixing a typo, like capitalization or minor spelling tweaks. If an admin—since they’re the only ones with the keys to change names—updates it for you, you won't lose anything; your posts, DMs, and settings all stay intact, you'll just have a new handle.
You can delete your own posts as long as they're still within the editing window. Once about five hours have passed since you posted (I think it's 300 minutes), you're out of luck.

And you can't just go deleting threads. That’s strictly for the mods, so if you’re looking to wipe a topic, you’ll have to reach out and ask one of them.

Do I need to politely ask the admin to change my username, or can I just do it myself? If I have to ask, where am I supposed to send the request? 🙂

Just ask the admin, Mr. Pes or Mi-24.
One of them might actually be willing to work with you.
I'm not positive, though. Bottom line: send in a request. But don't get your hopes up if you're looking for a total overhaul—they won't do that. They might "fix" a typo or add or remove a single letter, but if you're asking for a completely different name? Forget about it.

...basically...usernames are set in stone...but if you've got a legit reason, maybe they'll work with you. Same goes for deleting posts or threads (unless they break the site rules) - look, man, just think twice before you hit send...