Venom:
Eddie died in SM3 (see said skeleton). I believe Sony said they didn't want Topher Grace back for the Venom Spinoff so Eddie's death works...and if they do go with a darker route Topher wouldn't fit the role.
We also know Connors still has the sample, so it is completely feasible that something in SM4 could quickly set up the Venom movie. I know that it'd kinda suck to see the ooze in SM4, but they could do it very quickly and discreetly. IE the symbiote gets knocked over when Connors changes into the Lizard. We just see it crawl away....cue to the Venom movie where some new guy gets the symbiote.
Venom probably will go around wrecking crewing stuff and beating up cops at first until Carnage spawns out of him. Then he'll be forced to be they ultimate badass that they keep on trying to make him in the comics.
I really don't see Carnage NOT being in the Venom movie. Grace is out, so I wonder what they are going to be doing with the host.
Spidey Sequels. They've been trying to use Vulture, Black Cat and the Lizard for a while now in the movies. Hell, they even had Vulture in SM3 before Venom (which would've made the movie waaay better: less jumbled).
Here's kinda how I see it if they DO decide to finally use the character's they've been trying to do.
I know they are filming them back to Back, but are they supposed to connected? (I'll add something to tie them if need be)
Spider-Man 4: Lizard & Kraven.
Opens with Spidey fighting a B-Level villian (Rhino or Mysterio) It gets recorded and broadcasted all over the world...with the brutality of it, the situation, we get Junnifer Dugan back

...Kraven sees the fight and decides to go after Spiderman. Kraven encounters Spiderman. Connors changes into the Lizard (releases symbiote)...Spidey encounters the Lizard. Spiderman finds out that the Lizard is connors. Kraven begins to go after the Lizard (and still spiderman). Spiderman then has to protect the Lizard from Kraven while getting attacked by the Lizard. Then go back and inject the Peter/MJ, Doc Connors mentor stuff and themes: Protection (not that kind) of loved ones between these random happenstances.
Spider-Man 5: Black Cat & Vulture
Black Cat & Vulture: Black Cat steals from wealthy tycoon Toomes (like 90s cartoon) for some sympathetic reason. Spiderman goes after her, but she gets away. Parker Meets Toomes to find out why BC would steal the stuff and establishing the needed character connection bn Parker and Toomes. MJ meanwhile gets pissed about the BC stuff (Throw some Felicia Stuff w Peter to rise up the emo w MJ). Vulture starts Rampaging (maybe stealing tech or something) We find out that Cat is actually doing good through crime bc Toomes is doing wrong. Toomes comes out as Vulture...BC and Spidey team up to take down Vulture.
I think that would work, and if they use those 2 characters together it's probably close to what we'll get. I'd really like to see something different, like Electro.
So In conclusion:
Venom: Carnage
SM4: Rhino/Mysterio, Kraven, Lizard
SM5: Black Cat, Vulture
Spider-Man 6: Sinister Six (bonus!)
K. So the beauty of the plan (which is all above

t

is we could actually get the original 6 if they go this route with the movies. Doc Ock & Sandman reappear (have to retcon Doc's death) Kraven, Mysterio, and Vulture from SM4/SM5 show up and then introduce Electro. BAM! The ultimate theme here: With great power, comes great responsibility.