Generally speaking, the October Crisis was a disaster for the FLQ, which had been gaining some level of momentum during the previous decade. Even after the kidnappings, some mainstream Francophone institutions like the CSN, one of the largest unions in Quebec, we're sympathetic to the FLQ cause. The murder of Pierre Lapointe changed most of that. Quebecors as a whole rejected violent revolution as a means towards independence, bolstering the newly formed PQ and leading to the eventual election of Levesque, who advocated sovereignty via referendum.

The short answer is not really. Rene Levesque feared that separatism would become linked to terrorism and doom the future of the Parti Quebecois but this did not come to pass.

In the election of 1970 (held in April) the PQ received 23% of the vote. Polls prior to to the 1973 election showed similar levels of support. In December 1972, they were at 26%, and in May 1973, 25%. During the 1973 Election the PQ were first polled at 26%, then increased their support to 30%, which reflected the final results of that election as well. In 1976, the PQ received 40% of the vote, while the Liberals received 33% and the Union Nationale had 18%.

For the most part increases in PQ support was dependent not so much on the success of their independence agenda but on the failure of Premier Robert Bourassa and his Quebec Liberal Party. By the mid-1970s, the PQ and the Liberals had polarized the electorate so that an election became a judgement between the two. And, if you did not favour the incumbent Liberals, you likely voted PQ. Seperation from Canada was minimized in the 1976 campaign and instead Levesque and the PQ emphasized their leadership credentials and an ability to lead the province where the Liberals had failed.

We assume that the FLQ crisis had some impact on PQ support, but the evidence remains anecdotal. Pierre Marc Johnson joined the PQ almost in protest because he believed Trudeau considered all nationalists as terrorists. I have met Quebecois who explain part of their support for the PQ as linked to the actions of the federal government in October, 1970, though this was said to me 30+ years after the fact. Still, the polls I list above show that the FLQ Crisis did not have a large impact on PQ support, and from what I know their victory in 1976 was more a result of being seen as a second-choice to the mismanaging Liberals of Robert Bourassa than as some sort of revanchism against the federal government / ROC.