About every six months or so, the posts about how to use Rainmeter to replace the Windows Taskbar, Notification area, Start menu, and / or Windows Explorer seem to perk up. Given how powerful and flexible Rainmeter is, I can understand that.
Let me be clear though. Rainmeter is not a "shell replacement". It cannot even come close to replicating the Windows functions above. It is not what it was intended for, and unless you pretty much want to just live without most of the power of these functions, you either have to stay with the built-in functionality or use some kind of actual shell replacement.
You can create icons that can be used to launch an application, much like a "shortcut" in Windows. However, make no mistake. They are not shortcuts. The underlying windows functionality of a shortcut, right click properties, drag and drop on an application icon to launch, ect. are not something Rainmeter does.
Rainmeter can certainly be used to build something that "looks" like a taskbar, but it can't have applications minimize to it, it can't support drag and drop, it won't have active icons, it won't react to notifications from applications. In short, it won't be a real taskbar. Just something that kinda looks like one.
Most of the screenshots you see with no Windows taskbar and just Rainmeter skins are just using "auto hide" so the taskbar only pops up when it is needed. That is a perfectly reasonable approach. It lets you have your desktop look as cool as you like, while not sacrificing critical functionality.
You will see a lot of chatter about ways to disable the Windows taskbar, utilities that replicate some or most of the functionality of the Notification area, Start menu replacements and other tools like that. While I find most of them to be crippled or unstable or both, by all means explore alternatives as you like.
Just remember, as far as having Rainmeter replace the Windows shell: