I'm not particularly fussed with QB, if Luck isn't back I'll happily roll with Cousins for a few weeks until he is. Tyrod should serve fine as a 3rd for the time being. Not sure any of those are an upgrade on those 3.
WR- I'll probably make a play for Hogan if he clears waivers (not going to waiver him) but if I miss out I probably won't consider anyone past the 2 I mentioned (Josh Gordon and Anderson). Perriman.... I don't want to be tied to the Ravens never ending list of injuries, though if he's there for the UK game I might play him for shits and giggles.
RB- You've made me interested in Williams... and looking him up it sounds like he could potentially take over from Hyde next season when his contract runs out. He's definitely someone I'm considering adding now, I could even drop Yeldon for him so it doesn't use up one of my 2 free adds.
TE- Not bothered with adding future prospects given my group (Henry, Howard and Hooper). I think they'll see me through for a decade or so, barring disaster.
You're probably right that a DST and Kicker isn't worth it, I'll probably just rotate the 2 I have.