Interactivity Between Slides Using Variables

Hello!

I'm trying to make an interactive checklist with Storyline 360. I have it built out so that there's a "Table of Contents" slide with two buttons: one that leads to one topic of the checklist, and one slide that leads to the other topic. Both topic slides have several layers on them that can be accessed through hotspots over text organized in a table, and there are checkmarks next to the text that indicate whether or not this topic has been fully discussed (a button on each layer changes a unique variable, which automatically selects the associated checkbox in the checklist.)

My problem is two-fold:

1. I want to have the state of the buttons in the ToC slide change to "Disabled" once the learner has completed the checklist for that topic. I tried to do this using variables-- initially, I made it so that Variable1 would change to True when all checkboxes were selected, and if Variable1=True in the ToC slide, that button would be disabled. However, it's just not working. I've tried making the variable a value instead, I've tried adding in a button trigger instead of relying on the checkboxes, in case that was the issue, and I've tried making each individual checkbox add a value to the trigger.

2. I want to send the learners to a "Conclusion" slide once they've completed both parts of the checklist. However, much like the issue above with the buttons on the Table of Contents slide, I just can't get the variables to work for me. 

Has anyone else tried something similar? Is there a simple workaround that I'm just flat-out missing? Thank you in advance for your help!