Scissors symbolises that the Goddess cuts asunder the attachments to
this material worlds, much feared by the spiritual souls.
The first thing we need to verify is whether Goddess TAra is at all described in scriptures as holding scissors or not. If we can prove that she is not , then there is no need to answer your remaining questions.
Goddess TAra is the 2nd mAhAvidya. and, here is her dhyAnam from the Nila Tantram :
PratyAlirapadam ghorAm mundamAlA vibhushitAm |
KharvAm lambodarim bhimAm vyAghra charmAvritAm katau ||
Nava yauvana sampannAm pancha mudrA vibhusiTam |
ChaturbhujAm lola jihvAm mahAbhimAm vara pradAm || Khadaga kartri samAyukta savyetara bhujadwAm | KapAlotpala samyukta savyetara
ViswavyApaka toyAntaha swetapadma paristhitAm |
Akshobhya devimurddhanya strimurtinAgarupadhrik ||
Meaning of only the highlighted verses
Goddess is lolAjihva (tongue hanging out), chaturbhujA (having four
hands), mahAbhimA (terrible or extremely powerful) and baradAyini
(granter of boons). Goddess is holding in her right hands khadga ( a
sword) and kartrika ( a weapon similar to sword but not scissors, in
Bengali we call it kAtAri). And, in her left hands she holds a kapAla (skull)
and a padma (lotus)..... In her head, MahAdeva himself (Akshovya)
resides in the form of a nAga (serpent).
Goddess TAra's dhyAnam from Nila Tantram, Patala 4.
So, Goddess TArA is not holding scissors in any of her four hands at all.