you want to model an unweighted arm?

add vertex: use split polygon tool (read up on it's capablities)

second query doesn't make much sense
maybe post a picture?

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that's a "Ch" pronounced as a "K"

Computer skills I should have:
Objective C, C#, Java, MEL. Python, C++, XML, JavaScript, XSLT, HTML, SQL, CSS, FXScript, Clips, SOAR, ActionScript, OpenGL, DirectX
Maya, XSI, Photoshop, AfterEffects, Motion, Illustrator, Flash, Swift3D