I believe you've covered the major bullet points. I'd also consider a SCSI2SD, as even a working original is a likely failure point. The vast amount a storage is nice too!
A suitable PRAM replacement can be fashioned from a pair of VL-2330s and a bit of heat-shrink.
In addition to the much maligned plastic behind the hinges, check the mount points on the base into which the drive and logic board brass inserts are molded. All 3 of my PowerBooks had cracking & crumbling there as well.
As for the hinge plastic, there are a number of good solutions presented here on the forum, including a 3D printed reinforcement, but any of them should be coupled with a thorough cleaning and re-lubrication of the metal portion. For my part, I've had good luck with a) first roughing up the adjacent plastic, then b) JB welding the inserts back in place, and c) drilling through the other side and pinning the whole assembly together with qty-4 2.5x7mm flat-head screws countersunk into the lid.
Good luck with your 180! Mine has the dreaded LCD vignetting unfortunately. Someday I may try the oven technique...