Hey all! Got a calathea musaica just the other day - saw it in a shop and couldn't pass up this rare opportunity! Just a few questions regarding its health I hope someone can advise.

Its quite large and starting to bulge out of its pot and very root bound with loads of those big root bulbs at the bottom so it definitely needs some re-potting love although its not looking sick right now. Its very dense and a lot of the leaves in the middle are vying for space. Its currently in quarantine along with a few ferns I got at the same time as they all have a multitude of soil pests that I am waiting to deal with - I have a plan for that!

Should I re-pot it now or deal with the pests and wait it out until spring properly hits?

Should I consider propagating by splitting the plant into 2 when I re-pot since its so dense?

Its current soil doesn't seem great for drainage (and obviously full of critters). I'm looking at using a John Innes No.2 mixed with perlite maybe at 50/50 quantities. What would you advise I use?

Below you can see where the stems have grown its left behind little brown crispy leaf type things wrapped around the bottom. I'm assuming this is normal but what are they? Should I remove them?

What concerns me more is they all have this white mould looking stuff on them. Its only on the old brown bits and its not bugs (could be eggs?) and it doesn't scrape off. Any ideas what it is or if its harmful?

Thanks for any help! Feel free to let me know any other useful bits of info regarding this plant - I always want to learn as much as I can! xxx