Hi Lionelpx,
sorry for my delayed response.
But many thanks to you and your feedback. There are a lot of good points that I will take with me.
I will explain why I decide to do something you see now because I have no better solution or in my opinion, it was the best way.
1. Account creation
As important information, the password is NOT stored clear in the database! The password is hashed with a salt.
But you are right, submitting the password by email is maybe not a good idea. I will change this. Good Point!
I will work for a better position of ReCaptcha many thanks.
The email confirmation field, hmm okay I will think about it. (Was suggested by cms
)
The VEKN Number is a "problem" I want VTES Player as a target group, so normally all Users should have one. And if not you can enter "0000000" that should also be set as a note.
But the reason, why I want to have the vekn number is, that I can guarantee that I have unique users. Who are can be identified once, and can also only be found once in the database. And in some cases, some users would like to have an interface to vekn.net. So I have my "bridge" to this page.
2.Statistics
The problem, I saw in the past, was that the system is a bit complicated. And I don't want to have a lot of wrong or bad events are entered in the system.
So you have right that is a closed "group" because the only persons who get an introduction will have access to the system.
My idea was to get better quality for data.
The second (and maybe more important) problem is the GDPR, and this site collects a ton of data! And I will make sure, that everybody knows what he will do. Because if an event Manager inserts real names without permissions, I'm the person who is responsible for fails on this page. And I'm not interested to get post from lawyers. 
3. Site Map
Ok, you get me.
Yes, I tried to have a solution for everything... But I will go back to focus on the site.
TS3 was my favorite communication. But I understand "now" that the community would like to use Discord...so I will support Discord too
.
This Forum, was an idea to bring people like you to the idea to give ma any kind of feedback. But you and Igor are the once persons who gave me. But maybe I should link it as you said.
News should be in use, call me old schooled but I like the concept.
But will think about adding an opt-in newsletter...
Change layout will be removed... just a little playground from out of the past ^^.
The recaptcha is in use for logged-in user? That should not be... thanks for this. 
3.1. Feature idea: Grouping
Interesting idea, will think about it and will play around with this. Thank you
4. API
That is indeed a good point... And today it should be a standard ^^.
(I will make me a note for this
)
Feature idea: Open source
At this time I'm working on it to bring it to a git.
Many thanks for your kindly supply. If you have any kind of topics..please contact me. MANY THANKS