Re: suri waza
Hi and welcome to the forum.
There are some poeple who practise both bjj and aikido, but until they come along here are some of the more obvious points.
Suwari waza is a label for a whole class of techniques, it just means both partners are sitting down (seiza or keiza). It's purpose and meaning are something people could debate, but it serves a different purpose to combat base in newaza / ground sparring / "rolling." Horses for courses and all that.
When in bjj class, do as your bjj instructor tells you!