So, no more need for Kickstart update? This loads directly to ram like a rekicker?
Wait, what exactly is your question? A kickstart consists of several modules, and each module (except expansion) can be replaced by LoadModule. So, in principle, if you had all modules in the right format, you could replace pretty much all of it, yes.
LoadModule, LoadResident and SetPatch (and likely RemApollo) can replace modules. Of all the above, only the first three are still supported, and ROM-Module reloading has just been removed from SetPatch, which gives you two alternatives in the future, of which one is more powerful than the other.
Whatever pick you make: Select *one* tool, not four, for the same job.
As said already: "LoadModule AUTO" is all you need, once you setup your system correctly. Replacement libraries go into LIBS:, replacement devices into DEVS:, the Shell as Shell-Seg into L:, and the Ram-Handler similar to all Dos-Handlers into L: as well.