For the images that didn't load, I was able to get it to trigger for Anaya(a side character) but wasn't able to find anything at the clinic. As for how the bug is triggered, it shouldn't be possible for Anaya to reach stage 1 without using the dev console or a save editor. Quite literally the code for that does not exist in this release. I did create a new save and was not able to trigger the bug a second time, so there isn't much I can do.
For the gym gallery not unlocking, unfortunately due to how the gallery system works, it will only unlock upon them being seen and if you complete 'the second dose' the gym events with camille are different images. The gallery system I am using is the built in renpy one and unfortunately it is not quite built for this.
The new quests after reaching stage 2 are currently underdevelopment and if you reload your save, their objects will change to coming soon. An oversight on my part for how the quests are structured.
All of this will be fixed in the next update and in the course of chasing down your problems, I did find a handful of bugs, so thanks.