Not true what you've heard, haters told you that :D We have 3 vowels,, https://www.youtube.com/watch?v=7uCDeRSy-Zg
We use them in writing as well as speaking,,
About same script, I can notice some letters in Urdu, Farsi "Persian", Pashto, Dari,.. look like arabic letters but for example when I read the word, it's not arabic word and doesn't make sense. Some letters are close to arabic letters but not totally the same in the way we write, and some letters are the same in writing.
Also,I don't know if they have the same pronounciation for these letters or not.. as I told you before, different languages.
You are welcome at anytime.