IMO, there is no way to guarantee that you won't get a NFS clause. It's all in the hands of IMMI.How can I avoid 'no further stay' condition. Secondly if i get visit visa, how quickly can I get 802 visa and if visit visa expires in Australia can I get extension or some bridging visa while residing in Australia??
But you can request a waiver.
As to the timeline -
802 - Child (subclass 802)
75% of applications processed in 10 months
90% of applications processed in 12 months