I would like to answer your questions, as I found your reflection interesting.
1. If you stopped getting paid today, for any reason, would you post with the same zeal that you post today? And more importantly, if you weren't getting paid, would you really need to say all the things that you say when you get paid?
Well, I've been in a similar situation. I've been on the forum since 2013. Although I was more absent from 2015-2017 and 2018-2020, don't forget to keep an eye on the forum, I used to participate occasionally.
I can say that the incentive payment helped increase my participation and involvement with the community. But now, I don't think I would reduce my activity much. Maybe I would skip one or two posts, but I do over 40 posts a week, well above what the campaigns ask for.
I'm already very involved with the community, so unless things change very radically (and I'm not talking about payments), I should stay around. I say this from experience, since I have participated very actively in other forums without any financial incentive.
2. Would you support the forum to the outsiders, who would rationally wonder: "what on earth do all these people do there everyday?".
I didn't quite understand the question.
But I'll answer with a question: what do people do spending hours on social media (Facebook or Instagram)? I can't understand it, because I'm not there and I don't want to be, so the feeling might be similar.
3. Would you be actually interested in this forum's longevity and would you try to stop the scammers if you weren't getting paid? EDIT: I don't mean getting paid for moderation or tagging scammers, but I mean if you get paid and you need a sustainable payment resource through the forum, you gotta try to keep it safe, don't you?
I think the history of this forum has already proven that. Bitcointalk, from day one, has always been a strong community fighting scammers. The difference today is that people who deal with Bitcoin (and other cryptocurrencies) have stopped visiting the forum and using it as a research and protection tool.
Perhaps if they came to the forum more often, before participating in "wonderful projects," they would avoid many future problems.
Once again, I speak from experience. The forum helped me avoid falling victim to a major scam when I started dealing with Bitcoin. Unfortunately, I still I stumbled a bit, because I didn't take everything that was said seriously. Today I remain grateful for that and I haven't forgotten it.
4. Do you actually know (or use) the website or service that you promote? It's not a trap question, I just want you to think if you'd jump from campaing to campaign simply because of the money, or if there's also a tie with the service that you promote.
Well, I'm not a gambling guy.
(The reader should understand the answer I want to give.)I prefer campaigns that don't involve any kind of service, but I also value the trust that (some) campaign managers provide. Based on this, I decide whether or not to seek out other campaigns. Sometimes I might even be in a campaign I'd rather not be in, but because of my connection to the manager, I stay until one comes along where the change is significant.