Very surprised you are yet to win with Hertl, Grabovski, Kessel, Rask and Halak. Some of them are obviously not studs OR consistent offense capable but with the start these guys got, I would have thought you would have been up and brandishing Grabo and Hertl as trade baits (sell high). That opportunity may have come and gone, I am afraid.
Of the FA list you presented, Plekanec is the one that jumps out to me as roster worthy with the others being of the hit and miss variety. Niskanen could also deserve a look till Letang is out (in other words, short-term only).
Your goalies are solid, D is ok too (although the loss of Boyle weakens it).
See if you can bundle up Hertl, Grabo, Eberle or some combination in a 2 for 1 package deal for a better Forward, and pick up Plekanec from the WW to cover the missing spot that opens up.
League 1: 2021 Dobber Entry (Patrick), Yahoo Roto, 10 Teams
4C, 4LW, 4RW, 6D, 2G start; 5 Bench
Skaters: G, A, +/-, PPP, SOG, Hits
Goalies: W, Saves, GAA
Forwards:
C: Malkin, ROR, Backstrom
LW: Forsberg, Parise
RW: Gallagher, Hornqvist, D Brown, Kessel
Dual Eligibility: Svechnikov, Jamie Benn, Radulov, Domi, Rakell, Pavelski
Defense: Hamilton, Letang, OEL, Suter, Spurgeon, Girard
Goalies: Vasilevskyi, Lehner, Mrazek, Reimer