The glottal stop is dictated strictly by the use of the ʻokina in Hawaiʻian. You can't add it where it isn't written. Therefore, ”No Oʻahu” is pronounced like “No-Oʻahu”, with just a glide between the vowels, if I'm not mistaken. It would be somewhat like adding a “t” in between “Her” and “Reputation” in English; “Her trepuation” would most likely be understood, but sounds blatantly wrong.
English speakers have to make a conscious effort not to use a glottal stop when a word starts with a vowel - in English we add it automatically if the preceding word ends in one too (thus ”The apple” is more like “The ʻapple”).
Polynesian languages tend to have very close letter correlation. What ended up being a glottal stop in Hawaiʻian ended up being a k in Maori.
Certain regular correspondences can be noted between different Polynesian languages. For example, the Māori sounds /k/, /ɾ/, /t/, and /ŋ/ correspond to /ʔ/, /l/, /k/, and /n/ in Hawaiian. Accordingly, "man" is tangata in Māori and kanaka in Hawaiian, and Māori roa "long" corresponds to Hawaiian loa. The famous Hawaiian greeting aloha corresponds to Māori aroha, "love, tender emotion". Similarly, the Hawaiian word for kava is ʻawa.