After Nets general manager Billy King stole the show with his draft night trade for Kevin Garnett, Paul Pierce and Jason Terry, he and the Nets already have completed much of the heavy lifting to revamp their roster this offseason. So when free agency begins at midnight tonight, the task facing King, new head coach Jason Kidd and the rest of Nets front office is to try and find the right pieces to supplement the group King has put together, one that on paper looks as if it can compete with any in the Eastern Conference. But that doesn’t mean King doesn’t have some holes to fill, beginning with adding a point guard to play behind Deron Williams. This past season, the Nets had a strong backup in C.J. Watson, who shot over 41 percent from 3-point range — tops on the team — and also worked effectively playing alongside Williams as the season went along. But Watson opted out of his final year of his contract to test free agency this summer, and because the Nets can give him only a slight raise over the minimum salary he made last season, it is likely he will be plying his trade elsewhere. That potentially could open up significant playing time for Tyshawn Taylor, who spent much of his rookie season watching from the bench outside of a few brief cameo appearances — like when he scored 12 points in 34 minutes in an 89-84 win over the Pacers on Feb. 11.