Is there a difference between 'annoying' and 'bother'?
They use the exact same handshapes and location! Typically, 'bother' might be signed with a single, firm tap, while 'annoying' uses a repeated tapping motion to show an ongoing, continuous irritation.
How do I show who is annoying whom?
This sign is directional! If someone is annoying you, bring the tapping motion closer to your chest. If you are annoying someone else, move the tapping hands outward toward that person.
Do my fingers need to be spread apart or kept together?
Keep your fingers together. The description specifies the 'B' handshape, which means your four fingers should be straight and touching, while your thumb remains extended outward to create the crux.