Is it possible to copy custom forms, fields, and data from production to a development account?

I for the custom form, fields usually do this using SuiteBundles, I think you can also SDF for this if you are more. As for the data, you will need to extract then do a CSV import. If your development account is a sandbox account, you can just do a sandbox refresh. The refresh will make a copy of the production action at the time you requested the refresh.