Nouns / phrases:
Excitement, liveliness, activity, (over)stimulation. Busyness, bustle, flurry, preoccupation, multi-tasking.
Fuss, nervousness, stress. Difficulties with staying calm; inability to relax.
Traditionally: verbal communication; anything which has to do with voices (e.g. singing). For me personally: chatter, idle chit-chat, gossip, babbling, rambling, the blabbing of secrets. Short, often superficial, types of conversations, e.g. text messages. Obsessive brooding; incessant, compulsive worries; constant anxiety. Possibly small but persistent problems.
(Smallish) groups, meetings. Comings and goings, fickleness, unreliableness, unrest.
Chaos, lack of structure, lack of focus, distraction, difficulties to concentrate. Noise, clutter, disturbance, nuisance.
Reflex actions, quick reactions, presence of mind, quick-wittedness, repartee. Mobility and agility (literally and figuratively speaking).
Traditionally also: Old(er) couple, siblings (twins), a pair of something.
To excite, animate, (over)stimulate, agitate. To keep busy; multi-task. To (make a) fuss, alert, startle, get frightened.
To (verbally) communicate; talk over (and not listen to) somebody. To chat, gossip, blab a secret, ramble. To brood, fret about, worry.
To dither, fidget, change direction (or opinion) constantly.
To get distracted easily. To make a noise, clutter, create a mess. To be bothered or annoyed by something; to distract, bother, or annoy someone.
To react quickly (instinctively).
Excited, exhilarated. Animated, agitated, (over)stimulated. Busy, preoccupied. Fussy, nervous, stressed. On alert, not relaxed, skittish.
Verbal; voice-related. Talkative, gossipy. Brooding, worried, anxious. Obsessive, compulsive.
Fidgety, restless, fickle, unreliable.
Chaotic, unorganised, unstructured, distracted. Noisy, cluttered, all over the place. Distracting, annoying, bothersome.
Reacting, reactive, quick to react, knee-jerk. Quick-witted; mobile and agile (literally and figuratively speaking).
As a person: Person with the above attributes. Also:
someone with ADHD, multitasker, blabbermouth. Someone difficult to assess or who it would be unwise to rely on because they are so fickle.
Be watchful! Be quick! Negatively: Take it easy; calm down; focus!
Time factor *) : Something which happens soon, or quickly, but doesn't persist / attempts to rush it / everything happens at once.