Fierce/Dynamic:
daring
unpredictable
brash
powerful
bold
intense
chutzpah
charisma
sizzling
intriguing
Whimsical/Delicate
capricious
fragile
windblown
snowflake
dreamy
scatter
abstract
flower
flutter
pure
Safe and Efficient:
reliable
convenient
secure
friendly
smooth
established
automated
experienced
regular
slick