I'd suggest reading up on the breed. You can usually get useful breed-specific info that helps you head off problems.
I used to have a Siamese with a crooked tail when I was a kid. He was fine until we got him an older kitten as a buddy and the bud was hit by a car. He was inconsolable after that and would yowl all night. We tried to get another kitty, but she didn't like him and then died of Feline Leukemia. And then he did, too.
Currently, one of my cats (everybody's a rescue) is a Siamese kitten about nine months old. He's not a purebred, but he has all the characteristics of a sealpoint Siamese. Bless his heart, he is a little fella with a big personality, very affectionate and outgoing. I wouldn't go so far as to call him aggressive, as he's really just acting like a normal kitten, but he is superplayful. In fact, he will keep me awake playing (though he's getting better with that).
One of the most amusing things is that everybody else (including the dogs) has a big and distinctive voice. So far, he can barely manage a short squeak. He's sure working on it, though.
Animals usually settle down after a while, once they feel safe and feel they've got things down. Just give your new kitty a routine and gently guide him, and it should work out fine.
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I had a cat who had some Siamese. He was super intelligent and talkative, he loved to play fetch and hide and seek. I used to take my cats to shows and the judges would have a lot of band aids after judging the Siamese. They can be aggressive, but my cat would get over it quick.

We had a succession of three Siamese cats over the years, and they were wonderful: intelligent, eccentric, loving and communicative. They do like interaction with their humans and other household residents, and will care for critters who need protection. We were very fond of our Siamese.

They are very temperamental.
"Is it written somewhere? You should do what you want".

I have a domestic shorthair that has Siamese in her, and yes, they are quite the talkers! At first I thought something was wrong with her or she was just needing something, but her food was full, her litter box was clean, and she wasn't wanting to go out, so I just chalked it up to her talking to me. For the first week, she meowed all night and I wondered what I had done, but now we are all used to it. She does meow in the morning, but it's right before we have to get up, so it's like she has an internal clock and just knows, kinda cool! And, Siamese are said to be the most loyal and intelligent of cats, so I don't know if you ended up getting this cat you're referring to, but I'm happy with my decision!