Hey I'm super new to modular, would appreciate any feedback. I'm not sure if I should replace Atom with nRings and something else instead.

you could replace the atom with a full size rings - that way you would be showing Emilie how much you appreciate her work - instead giving all your money to cloners - but that's up to you!! - you may liked cramped,modules with minicontrols - I don't!

the modules that I would remove from this case without a second thought though are the plasma drive and the listen i/o

plasma drive - it is just too big you would be better with a 4hp one from Noise Engineering

the listen i/o is redundant the nifty case already has outputs built in and often they are not needed anyway!

if you replace the ATOM with an OG Rings, the plasma drive with something from Noise Engineering and dumped the listen i/o - you would have an extra 22 hp

I'd add a passive attentuator and Maths - check out the maths illustrated manual online to see why this is one of the most useful modules in modular synthesis

The best advice would be to get a bigger case - a Mantis perhaps - and go slowly