Subjective. That depends on what features of Pro are you currently using. Would you please clarify?
Of course, the test can be executed from Jenkins.
For different environments, use external properties file for configuring environment specifics. For example, use separate file for each dev.properties, qa.properties, production.properties for environment specifics and pass the respective file for the execution as per the environment. This each property file can include the data ranging from data base, to endpoints.
If someone can handle or write code for the custom needs(if any), then SoapUI OS is pretty good enough to use. Of course, it may take some time to implement and require more programming skills like a developer. For QA engineers, thats where Pro helps to get things independantly and little quicker.