Creating Custom Properties:
bpy.types.Object.custom_float_vector_temp = bpy.props.FloatVectorProperty(name = "Force Application Temp")
Set to Obj/Edit mode:
bpy.ops.object.mode_set(mode = 'OBJECT')
Select all objects: (Can replace SELECT with DESELECT for deselecting all, works in edit mode too for verts/faces/edges)
bpy.ops.object.select_all(action = 'SELECT')
Set edit mode (face/vert/edge):
bpy.ops.mesh.select_mode(type = 'FACE')
Get active object:
bpy.context.active_object
Flowchart for diss @ https://app.diagrams.net/#G1wQDt6sTcFuspLHn4elXabmbRPKbr9Xtv