In case you haven’t noticed yet, we have just released a new form builder! The new builder phases out Form Fields (e.g. objects where you set all options related to how fields behave on forms) and now lets you set default and custom field behavior from within your forms. This allows you to have fields that behave differently (required / optional, labels, progressive profiling rules, etc.) on various forms, without having to make more than one version of the field.
Then set any options related to those fields from right inside the form. That way you can have a field be required on some forms but optional on others. You can also have different labels for the same field depending on the form in which it is used. This is perfect for internalization (e.g. using labels in a foreign language without needing to make new fields).
You can also set more advanced options like progressive profiling under the Advanced tab. This allows you to have fields be conditional on some forms but not others.