Hey @kelseyingram392 
- answers below:
- Can you use custom object properties as Active List criteria?
- Not at the moment, but we’re working on it!
- Can you deduplicate/merge custom object records?
- Not yet. Merging custom object records is in development, but we don’t have a timeline for adding manual deduplication functionality (described here) to custom objects at this time.
- Can you still create custom calculation properties based on associated objects?
- Yes, you can create calculated custom object properties using associated object data. For the record that’s one of my favorite CRM features! The process is the same as with a standard object - more info here.