Word's 'widow/orphan control' option ensures there are at least two lines of text for a given paragraph on each page over which the paragraph is split; it doesn't really have anything to do with headings. The 'keep lines together' option is meant to ensure all lines of a paragraph are on the same page, which is quite different to what the 'widow/orphan control' option does. To ensure the 'widow/orphan control' applies to every paragraph that might require it, don't adjust the paragraphs one at a time; simply modify the paragraph Style by checking the 'widow/orphan control' option. If you want to avoid having a heading at the bottom of one page and its content at the top of the next page, use an appropriately-formatted Heading Style with the 'keep with next' paragraph attribute and no empty paragraph(s) between it and the related content.
CreateSpace.com has its own standards for margins. See the discussion at
https://www.createspace.com/en/community/thread/6242, for example.
If you want accurate page layout settings, I'd strongly recommend using the menus. See, for example:
http://www.augustana.edu/student-lif...rd/page-layout