animation project going on and need urgent help about common issues

hi everyone,
right now i m working on a campaign for NGO about AIDS targetting children (street)
this is first project i m working in blender.
assets creation is almost over, getting ready for animation

about rigging common questions / workflow
we have 5 characters, all biped (kids models, etc)
1- i have finalized 1 rig. right now. all cases are same and i m hoping to copy paste skeleton / armature, modify this and reuse for other models ? is that ok? would there be naming issues. i can imagine, i rename main armature object n datablock as per character, rest of bone names will be similar, not sure, it will be issue or not

2- right now heirarchy is like
armature is most parent / root , there are bones inside this, few meshes (character face / body / eyes> parented to head bone)
problem a:
i have added controllers curves, in scene, which controller bones are using as display object. >> what is best way to deal with them
option 1: just put them inside armature by parenting them to armature
option 2: just group them??
option 3: hide them in a layer (but they still show in main scene outliner, which seems bad…
problem b:
i have also create driven keys for face shape keys, few objects in scene. all parented under an object faceRig. should i simply make this child or armature object or what?? so i can have one main object in outliner per character, rather then too many nodes and scene getting messed / clutter…
please feel free to advise.

about animation
1- how to display trajectory in viewport.?
2- is it possible to edit trajectory or not??
3- is it possible to change keys size ( width / thickness for display)
4- can i select a keyframe in timeline and move it (e.g, few frames)

5- how timeline display keys?? is it selection based of bones or just armature?? >> lets say, 1 arm has 3 keys at (5,10,15) frames. and second arm has 5 keys ( 5,10,15,20,30). right now timeline display all keys in total, is it possible that when i select right arm, only its keys are displayed in time.

6-

i found trajectory thing. its inside scripts >> animation >> trajectory.