Can an arcane focus be part of a 2 handed weapon or a single weapon ?

Can a arcane focus be part of a two handed weapon or a single weapon , like a clerics holy focus can be part of a shield ?

What is the extent of control of a warlock over her Thrall?

Mage Hand is attacked… what happens?

With the wizard Spell Mastery can you choose two first lvl spells but have one be at cast as a 2nd lvl spell?