I had such a hard time finding /ɪˈpɪt ə mi/. I tried so many different spellings that I ran out of ideas.
However, mnemonics and pneumonia are just diabolical. There’s zero chance that you’ll ever find those… which reminds me, this new language would have to be very big on silent letters. Basically like French, but cranked up to eleven, because anyone foolish enough to study this language deserves to suffer.
As there are vastly more vowel sounds than there are vowel letters, you might as well use only consonant letters to write all the vowels. This language is just one big middle finger to all the other languages out there.