For a start, you don't have to open a 'nice topic' as you put it. You just have to post and all it takes is 5 members to notice how well you're posting and you're in. You never have to make a topic.
There are many reasons why it's like this. To stop inexperienced forum users failing to post links, pics and vids and making a mess of the forum. It allows people to learn the rules, etiquette of the forum, the standard of the forum. It deters people who just want to use the forum to sell. Keeps out the spammers. The list is endless. There's nothing that you can't do in new members that you do anywhere else on the forum other than buy and sell. And if you've come on this forum because you want to sell something then in lue of paying fees via ebay you'll have to be pacient and wait until your validated.
TF is somewhat a dictatorship, as it's a private forum, the admin can do whatever they like, they don't have to answer to anyone. Although the admin always discuss what's going on with this forum in the SM (hidden) forum and often ask the regular members.
Exactly your problem. The ironic thing is, you could have metaphorically exploded, but if those security checks weren't in place you are at risk of literally exploding. I'm sure you'll complain about it either way.