Red and green light event is pure nonsense. In my 15 years of gaming experience I have never seen an Event this badly designed...

What are you finding so difficult with it? Like any good game/activity, there is a learning curve. Once the mechanics are known it's just a matter of being patient during the game and a little bit of practice.  

You know that an event is badly designed when there is no skill involved in it and everything around it is based on RNG. Now, let's look at the red and green light event:
1) Female NPC turn around at random and instantly. There is no rhyme of when she will turn and she turns instantly. So, you have to stop moving at random and hope for the best. There is no skill involved as you will never know when she will turn;
2) Sometimes balance metter fails you in less than 0.5 sec and you can't react at all. Sometimes it starts right in the middle and doesn't move at all. Sometimes a click into the opposite way barely moves the meter. Sometimes one click in the opposite way launches it so hard that you instantly fail. Sometimes the balance meter works very fine. You will never know what you will get and you can't "learn" or "practice" random events. There is no skill involved in overcoming this, it is solely based on whether or not you will get a lucky RNG;
3) There are no preparations and no explanation of what and how this event works. You just have to jump in, fail many times in the row until you figure out that nothing you do matters - this event is all about RNG and if you get lucky, then you will complete it. If you get unlucky, then you will have to try again. All the "patience" about this event is based on how much RNG you can withstand.

This event has no learning curve - there is no learning in RNG. This event is horrid and badly designed. Had bad RNG for hours until I got a perfect row of moderate balance and long windows of movement. Have never ever seen a worse event in an MMO, and I have been playing MMO's for 15 years.

Ah, I see. Well I can absolutely help you (hopefully) out;

1) There is a way to predict when the shai robot turns around, once you learn it you'll never have a problem. Hint; listen to what it says/sings (i.e. turn on your sound, and if still having trouble turn off in-game/out-of-game music etc.).

2) The balance meter can be tricky yes. Just like training a horse skill, sometimes it's harder sometimes it is easier. However if you're ready you can almost always react in time. For me personally I have more trouble with the 'up/down' balance game compared to the 'LMB/RMB' one, so I'm always prepared for the former. Sure, sometimes I still fail at it, but so what? That's life, failure is not a dirty word. Nothing worthwhile is ever easy.

3) Well that is part of the enjoyment of the event really. Too often in game (especially BDO events) we're handed things basically on a platter with no interaction or thinking involved at all. It's nice that PA is introducing these events that gives us the opportunity to figure things out for ourselves. And of course - like is the case with everything these days - if one can't be bothered to figure something out, or are stuck still after trying, etc etc, there are plenty of guides online (video or otherwise) for almost everything.

Hope this helps.

I know, and it is still random. Sometimes she turn around right after she stops singing, sometimes she turns around after a delay. Sometimes she sings really fast, sometimes really slow, and she sings in some made-up language. As I already said - RNG.

No, you can't "almost always react in time". It is completely random. Sometimes balance meter doesn't even display as it fails before it gets displayed. It is very badly designed.
The key issues is that it is badly designed. Good desing would mean that you can learn how things work and by knowing how things work you complete an event. However, no matter if you know or don't know how this event works - RNG still fails you.

Well, if you enjoy a badly designed RNG event, then good for you. I didn't enjoy it one bit. It is a boring RNG based event where you don't need any skills and you don't need to think at all, you just need good luck and loads of free time.

No event is prefrered to an event like this, because it is time-gated and you will feel like you are missing out if you don't participate in it, but participating in it is a horrid experience.

Well no, I don't think you're actually correct there about a couple of things. But from the tone of your somewhat aggressive writing, I think it's best just to agree to disagree.

Worst of all is the waiting. Why this event not in a continuous mode?

There is also no room for a mistake (or lag). If you fail minigame (or mini game lag on start so marker is out of scale on start) you don't have time to return, take it next robot and finish. Nope, you need have to wait for next round.

Let's not forget about the biggest failure of this event: house of horror which probably 99% of players used a bug to see obstacles and only then were able to complete it.

I've probably tried 50 times already and ... I failed. The third room is a failure. You can't take even one step and you can't see where the box is at the start. One mistake and you start all over again, and again you have about 10 obstacles before you even get to the third room.

The wait had been reduced to 3 min which is much better, and you can actually fail and still complete on your second attempt,  I have done so myself. 

The last room in the House of Horrors is tough,  you have to be very careful. And sometimes those red-lantern wraiths can get you practically without warning. it's a toughie, but still doable. It's still primarily a memory challenge.  

No, no, and no.

If you listen to her, you'll know when to stop moving, she sings at different speed but she always say the same "words", so the end of her song is totally predictable. 

Based on that, your only goal is to make sure you completely stop moving just  before the end of the song. 

If you stand still when the mini game appears, the mini game won't suddenly show you a cursor moving at high speed as soon as it appears. The only random thing here is to know if you'll have to do clic left/right or up/down.

Do that patiently until you reach her and do the final mini game before you can talk with her and get your reward.

And it's coming from someone who succeeded at the first try this week. Literally, this is child's play.