Just from that paragraph alone you typed, the story became ridiculously complex, this was one of the issues with G1 as it neared it's end, the story became very complex and convoluted to follow.
The barraki are currently not canon, and you're bringing the vortixx, Mahri, the Skrall as a race out of nowhere. Roodaka has had some pitches in the past (@A2B2C2) but I'm not sure if she fits within this canon, the Kahgrak Nui may be a good idea as a set Rahi though, I'll give you that.
The better pitch is having the visorak as the "elites" of the skull spiders, their leader being sidorak, this pitch is simpler to implement and for readers or viewers to understand. They could have originated from another island and have been brought to Arthaka by Makuta but it's best to leave the Vortixx and Mahri out of the Skull spiders for now.
I'll be updating the main post pitch with the skul-spider/visorak pitch soon.
Edit: @Sanokal is indeed correct that these are not separate species, but factions of Matoran.
Edit: Main Post updated.