Sort of yes to all .... better answer may be available!
The base Genesis figure and functionality are supplied with the software and content. Genesis is different from the ‘old’ Gen 4 figures such as M4, V4, etc., by being ‘all things to all men’: Genesis as standard is a gender-neutral character, with morph dials available to add male or female shaping, or a combination of both. Victoria 5 and Michael 5 add additional morphs to give the latest version of the Vicky and Mike stable, along with new UV maps (Genesis can use V4 and M4 UV maps, meaning that all your old skin textures can be used on Genesis) and textures.
Clothing meant for V4 and M4 can be loaded onto a Genesis figure, with quite good results generally - though heeled shoes and some dresses/skirts can have issues. This is via a process called auto-fit: just tell DAZ what the item was originally for (from a drop-down list of supported figures) and as an optional ‘hint’ they type of item (again, from a list).