First. No. An arbitrary 2-post minimum is not the only thing swaying the tide of endless bot-spammers. More likely account creation gates in place prevent the majority of bot-spammers.
For new accounts, I detected at least two such mechanisms. Email activation is an industry standard and does a good job on its own. But before that, the CAPTCHA-like question I was asked during account creation gave me a bit of a chuckle ("Fill in the blank: Delux P..... IV"). The Venn diagram of folks creating accounts here and and folks able to fill in the blank on a software package published 30-something years ago might not be fully eclipsing circles. It immediately got me wondering about what the experience might be for would-be users who do not have that tidbit of trivia in their brains. Lucky for me, I didn't need to find that out first hand. I'll assume if I didn't know that one, it might let me keep trying until I got one I did know. Cute, but unnecessarily complicated.
My account creation use case is not likely unique. I have been aware of AmiBay for quite some time and only decided to create an account when one such search resulted in a product I needed for a project. I've reconstructed three Amigas from refurbished and new stock and was wanting to start a reAmiga 3000 project. Chucky has a still-active listing for his boards and I wanted to reach out to him to purchase one - per his own instructions. To do so, I needed an account to first declare interest then follow up with direct messages.
Your faith that the average user is going to spend time reading even a small part of the information they are presented is misguided. Show of hands for the number of people here actually read the Terms and Conditions before agreeing to them? Email about Forum Rules? Easy: don't post inflammatory messages in public forums that might offend the mods. Check. What more could it possibly tell me? Don't need to burn calories reading that... Now where's that direct message button?
See why we're here?
Now you absolutely have a point - it's your website and if I don't like the rules, I can go elsewhere. And also my point. The internet community is fickle. Speaking as someone with 30 years of experience in this industry, frustrating your visitors even for a moment is enough to ensure they won't come back. I understand the line we walk trying to thwart ne'er-do-wells while keeping the good ones engaged. Based on my first post here, I'm clearly in the former group. Mission accomplished, I guess.
For my tone, I do apologize.
What I should have said: as a new user some of your policies have been very frustrating and there ought to be less-intrusive methods to accomplish your goals. It has definitely prevented me from completing my first transaction here, and I'm not sure I'll be back to try again.