Not necessary. Ansible is not needed to integrate Node-RED with Hubitat (or Home Assistant) for that matter.
Simplify relative to what? And what "alternative devices" are you referring to?
You need to install HADB on Hubitat. Nothing has to be installed on HA, although you'll have to generate a token. You can read all you need to know about installing HADB here:
You need to install @fblackburn's Hubitat nodes for Node-RED. His integration requires the use of MakerAPI at the Hubitat end. Of course, Node-RED needs to be installed on any platform that can run Node-RED. I use Ubuntu, but others use Windows or OS X. You can find all you need to know about installing @fblackburn's nodes over here, including directions on how to configure MakerAPI.
Many have also found this website, created by @csteele, to be useful in configuring and using the Node-RED integration for Hubitat.
