(1) Lord Howe Island; (2) Island nations 

(1) Lord Howe Island is not in the list of "Other notable island mountains". Would someone like to add it? I do not feel confident doing it myself. Its highest point is 875-m (2,870-ft) Mount Gower.

(2) I don't understand the comments about Guam and Rügen, as the list of "Other notable island mountains" never purports to consist exclusively of island nations, right?