Is this a deadly mixture of martial arts?

Here we go with the d34dly again. Stop being focused on being d34dly and start focused on being a good, well rounded fighter. Capoeira isn't deadly, its glorified dancing. It will get you KILLED in a street fight. Whats the point of learning Muay Thai and Boxing? They're both stand up arts, and it will only serve to confuse you. Pick one or the other. Jiu Jitsu is perfectly fine.

I suggest doing Muay Thai and Jiu Jitsu. The combination of the two will make you a well rounded fighter.

Why not take it down to just two which is going to be much easier to learn in practice and do Wing Chun and Judo?

Its a good mixture for a street fight with bear hands but believe me if there were any weapons with someone who is expert in using it you can't do anything against it but in kung fu you will learn how to throw away weapons and how to dodge them

If someone tries to learn that all at once, especially if they want to learn it quickly, they will be mediocre at all of them, if not completely terrible. It's probable best to just stick to one martial art and really try to master it over time than to really suck at a bunch of different martial arts forms. Especially in a street fight situation where the mind is racing and the adrenaline is pumping, you don't want to be thinking too much about what "style" you should use.