You are missing the point... just because they pass hugs & kisses, shed tears together, and said I'm sorry does not mean everything has been resolved. Flint is a killer, a majot threat to the community, and is a fugitive. Spidey can not just allow a known criminal, with powers now, to wonder the streets. That goes completely against, "with great power, come great responsibility". Spoken by the very man, that was killed by the fugitive Spidey let go.... in Sam adaptation.
Look, Sandman has killed a number of officers, never promise anything to Spiderman and virtually told him he will not allow anything to stand in the way of him helping his daughter, so obviously he's not done commiting crimes... oh, and did I mention he's wanted criminal who now has superpowers.
Really, I am more disappointed at Sam killing Norman & Harry than I am him killing Eddie/Venom. However, since the discussion centered around setting up Brock verses closure & uncertainty... I put the sad face next to Venom.
However, maybe it's just me, regardless of the uncertainty of a SM4 film, I still would tell the story I feel needs to be told. If I return, I'll pick up where I left off; if not, than so be it. Rushing a character, not doing proper development, forcing closure, because this may be the last; to me, shows lack of real commitment to himself. I don't know any other way to put it.