Was the word for the BDSM costume "gimp suit" coined by Tarantino in Pulp Fiction?

EtymOnline has this:

gimp (1) 1925, "a crippled leg," also "a crippled person," perhaps by association with limp, or a corruption of gammy (see game (adj.)).

gimp (2) also gymp, ornamental material for trimming dresses, furniture, etc., 1660s, from Fr. guimpe, O.Fr. guimple "wimple, headdress, veil," from a Germanic source (cf. O.H.G. wimpal).

It agrees with your sources on etymology of gimp as a slang word and sheds some light on it's "fabric" meaning, which seems to be at least several hundred years older.

As to gimp suit, it seems to be coined in Tarantino's Pulp Fiction (Wikipedia) and is younger than both above meanings of gimp.

Gimp suit as a BDSM term is believed to have originated in the late seventies or early eighties, although its original usage differs slightly from what we are familiar with today. It does not originate from the Quentin Tarantino movie Pulp Fiction. It can first be observed in erotic BDSM literature around the described time period.

Based on some of these texts, it seems that the original "gimp suits" were more of a complicated full body restraint than a full body harness/shame-cover as they are more typically viewed today. A common theme in a lot of bondage play was the limitation of the submissive's ability to move, whether it be via handcuff, leash, or restrictive clothes such as corsets. The "gimp suit" originally expanded on this idea, with several latch points for external restraints, stiff fabrics and even stiffer reinforcements, and various other points of restraint.

The gimp suit was a veritable full body restraint. Although I have no confirmation on this (I wasn't around to watch the conception of the term), it seems most likely that it was termed a "gimp" suit because it essentially handicapped the user, making them a more classical "gimp." I've discussed this terminology before, and that is the best I've ever come up with. Today, gimp suits are more an objectification and humiliation tool, meant more to degrade the wearer to a sexual "toy" as opposed to partner. However, many suits still retain the original idea of restraint.