100% is the best way to run Corpse Party imo. It gives depth to the run outside of optimal movement, making you decide when's best to save to avoid repetition. I use the rules below for the 3DS version that includes everything you've mentioned, though I haven't actually had a chance to do a run since uni stuff got in the way. Hopefully this helps though.

EDIT 1: As an additional note, the extra chapters are the thing that have me conflicted with this category. When should you play them? And assuming you start from a fresh save like you said, wouldn't you unlock extra chapters for beating Ch. 5? Just a few things to consider.

EDIT 2: Also, how would you regulate JP vs US regarding all name tags? Since you can't actually get every tag in US. Would US be banned, or would JP skip the unattainable tag? PSP version seems a little more annoying to plan than 3DS lol

I'm not too well-versed in 100% runs, so if somebody could propose a modified version of the 3DS rules for the PSP version I'll get the category up and running.