Office 365 on the web works well on Linux if that has enough functionality for you. If not, the only way to get a modern version of the real Microsoft Office is in a VM. Older versions will run over Wine.
As far as alternatives go, OnlyOffice has the best reputation for file compatibility. I use LibreOffice and am very happy with it.
Avoid OpenOffice. It is really just an ancient version of LibreOffice.
That is not what he said. First, he means that the distro is KDE-forward and using that desktop environment by default. Second, he said that KDE was “non-vanilla”. Third, he suggested that the distro has extended KDE with its own utilities ( a more focussed version of the second point ).
To illustrate the difference, Ubuntu is a “bigger distro” but not a KDE one whereas Kubuntu is a KDE distro.
Red Hat does not package KDE ( which I assume means Rocky and Alma do not either ). You have to use a third-party repository to get it. Chimera Linux does not have KDE. I am sure there are others although it is not something I have paid attention to.