I'd definitely suggest that one learn kana as quickly as possible. As for me, I studied in university using the Genki series. I believe we started off using romaji just to simultaneously learn some vocabulary while we were studying the kana. Don't remember perfectly, but I think only the first chapter or two used romaji. Romaji is a crutch, and a bad one at that; it's difficult at first, but if you want to seriously read/study and Japanese materials, you need to be able to quickly read kana.

It depends on your goals. If your goal is to be literate, then you’ll learn kanji and kana from the beginning. If you only want to learn to speak, then I’d say ditch text completely and go for audio. In that respect romaji is only useful for talking about Japanese in a non-Japanese context (and to be fair, learning to type Japanese).

To be completely honest with you, I wouldn’t trade my Japanese literacy for anything. I wouldn’t be able to chat with friends, read comics, blogs, news, or Wikipedia, or anything really.. The fact that the Japanese use a different writing system from English is what separated it from other languages that I might have considered learning. So I can’t see why you’d want to do away with it. Besides, it’s fun and rewarding to learn another writing system.

Don’t knock it till you try it~

I don’t think a few of these count as reasons.

“Kana is real Japanese.”
Just because it isn’t ‘real’ doesn’t mean it’s bad. If a Russian was learning English, for example, I’d suggest they transliterate it to Cyrillic first if they want to learn quickly. ”Kana gets you on the right track.” Only if your goal is to read, and you don’t mind using some extra time to learn the Kana. 
And It’s worth mentioning that Romaji allows typing in Japanese.
Other than that, I completely agree. But I sort of support Romaji more because of how much people unjustifiably hate it. It can be very VERY useful. I suggest learning both at the same time, there’s nothing wrong in writing it in a familiar alphabet. But like when I started learning Chinese, I’m gonna learn by the Roman Alphabet (or maybe the Cyrillic Alphabet, probably more fitting), simply because it will reinforce the language more to me by presenting the words in a familiar shape. (since word shape is hard to recognize in strange writing systems)

hey , i speak hebrew , english , portugues , and italian , then the romaji will be the easier choice for me.
if i would learn only romaji , then il be able to just speak right?

It would be easier, yes. But you won’t be able to only speak, you’d also be able to write using Romaji based typing input-methods. 

You wouldn’t be able to read though. 
Essentially you should learn both, if you want to fully understand Japanese. It’s all up to personal preference. I really support using Romaji simply because many learners of these types of languages get immediately discouraged from being overwhelmed by the syllabary alphabats (Kana) and the logographs (Kanji). 
Use the Romaji as training wheels, while slowly learning the Kana and making your standard. 
But all in all, you should learn reading and writing in the native system. That’s very important. The only question is how to get there.
Good luck with your language learning.