I think in any language, if you use the masculine form for a woman, it will sound weird, but OK, because it is like... the standard. However, if you use feminine to men, that will sound offensive.
For example "Thank you" in Portuguese is "Obrigado" (the standard form) If you're a woman, you'd say "Obrigada". If a woman says "Obrigado", that's ok. But if a man says "obrigada", that would sound weird.
In Italian, there is a separate word for a male doctor and a female doctor. In English, there is not. When you give a translation it has to be in correct English. So, dottoresse is just "doctor". "Lady doctor" is wrong because it not a proper English word. See here:
The double consonants are held longer which may result in it sounding like two words. Doubles are not divided into separate syllables but for a newbie it might be taught that way to help you with the longer held sound.
A similar problem is the "z" and "tz" sounds in The Leaning Tower of Pisa or Pizza.
Check out number 5 in this link. :)