Hi Kris welcome to the forum
Can we assume these 8 new lamps are down lighters? The custom "8" holes or terminations in that rose would be 3 permanent or loop LIVES, 3 NEUTRALS and 2 SWITCH/LIVES. So you really could not fit 8 cables into it ?
I would normally replace the rose with a suitable junction box and then as you say bring a SWICH/LIVE & NEUTRAL from the JB to your first fitting and then PARALLEL loop, not series so on.
Yes I would have a Junction or connection box at each light for easy connection especially if these are downlighters.
Now this is where it gets interesting, depending on how you install these, those junction boxes should either be accessible of testing, or the newer "maintenance free" type that are in line with the current regulations.
Now I know that mostly non electricians would say this and that, and just but it into a connector block and shove it back up .................well you have asked your question on an electricians forum, and so you will get advised as to good practices and the regulations.
So it's up to you, the proper way as I have said or not