The undoing

[RC James]

A thread so soft,
smooth,
gentle,
coy,                               I think that, throughout this you're making lists, of attributes or feelings, and your reasoning may have been that this would                                                           clarify but I think it confuses rather.  For instance, you use "coy" here to describe a thread, "soft, smooth, unraveled                                                             would suffice.
unraveled.


Bit by bit,
fiber upon fiber                          
of velvety decadence.                        I don't think you need "bit by bit"  -  "fiber (up) on fiber works for me. on rather than upon
A gush took it over
of the wind; disheveled.                      ..."took it over/ (of)? the wind  synatax is skewered


With it modesty,
animosity, affections,                       This and the final stanza need some more explanation. something's been knitted or woven and in the end it's come                                                                 
passionately fluttered.                       undone and the person with it, but "modesty, animosity? affections, seems an overload, choose one and expand on                                                             it slightly so the reader can connect.


On the ground then
I saw what was left,            Seems you don't need uninhibvited, the work is uraveled and it might be the pérson who is undone.
unraveled
uninhibited;                             Hope this helps, Cheers, RC
undone.