If you are using AEM forms cloud service the feature to store in share point is provided out of the box the release is expected to be end of March 

com.adobe.aemfd.docmanager.Document pdfDocument = new Document("crx:///content/dam/formsanddocument/samplepdf.pdf"); https://developer.adobe.com/experience-manager/reference-materials/6-5/forms/javadocs/index.html?com/adobe/aemfd/docmanager/Document.html

Will send you sample

Which component?

yes, with AEM Forms Cloud Service it is straightforward. We have ootb connector for storing form submissions in sharepoint. This feature will be released soon

https://eslifeline.wordpress.com/2008/06/04/importing-and-exporting-form-data/

You will have to do something like this radiobutton.values=[“A”,”B”]

You cannot hide the values inside the radio button , you will have to just replace the values  https://experienceleague.adobe.com/docs/experience-manager-learn/forms/adaptive-forms/choice-group-items-adding-dynamically-article.html?lang=en

so to understand your requirement correctly RadioOption A contains the following choices  1 2 3   what do you want to do if the selected value is 2?

Use the rule editor, that way you do not have To write any code