Alright, you're right, Quilt. I didn't mean too come across with the mindset that anybody who uses 'funner' or any bad grammar means that they are automatically considered dumb or stupid. Yesterday, I went back and edited some things to try to get rid of that sentiment, but I guess I didn't do that very well. All I'm trying to say is if you use words like 'funner', most likely, people will consider it to be incorrect. That's why teachers will mark off on your papers, the textbooks say it's nonstandard, and the "grammar nazis" start so much crap about it.
And about that grammatical error I made; my bad. You got me. I was typing it up quickly and multitasking. And I'm too lazy to check my work, at least when it comes to an internet forum. It's a personal problem I have. My bad, okay? But, I acknowledge that error and could've re-read my passage and fixed it. I understand and follow the rules of grammar. It was nothing more than a typo. Speaking of grammar rules, I get your 'pants' thing. English is a kooky language, but it is what it is. We all accept the 'pants' thing and the possessive thing, because that's just how it is and we're all cool with it. And, as a majority, we don't accept 'funner' as correct grammar. It is how it is.
And I do not consider 'funner' to be slang. To me, it's just effed up grammar. Those computer terms you used, AltF4, are mostly all slang, or maybe jargon, rather. But even they don't all have the same quality, other than being generally accepted in soceity. Like, fubar is just acronym that people cutely made into a word. Firewall is tech jargon that is the only way you can describe what it really is. The original definition of 'firewall' has nothing to do with computers, of course. But, it has been, to take a page from you, fully assimilated in our common speech. Oh, and it's Bluetooth, not bluetooth. It's company, a trademark, and a proper noun. Not slang.
To answer your question, yes, they are words. Funner is a word. And I understand that it's the title of this thread, but I didn't think that was your problem with it all. I thought you had an issue with the "Grammar Nazis" giving you crap about it. But you can't debate your way out of that. You can't argue away how people feel about it or what they've been taught or what it's being taught now. It does not have the same slanglike qualities to spread throughout the country like the computer jargon. And that might be the teacher's or the textbook writer's fault. Hell, it is their fault. But, it's their job and it is not a bad thing. In fifty years, it will not be in everybody's common vocabulary. It'll be in the same place it is today, or hopefully, it'll be dead.