I cannot be the only person curious about this stuff (SA 2019 edition)

Given how ridiculously early the applications for SA 2019 programs opened this year, I have a few thoughts/concerns/questions:

1. If the applications close in the fall, will they continue to consider new candidates until then? I understand that they have probably handed out quite a few offers but I am sure that applicants have applied to multiple firms and have, therefore, had to turn down offers as well. I have heard that several firms give you until the end of the summer to decide, so there is time to hear back from other places. This leads me to believe that spots may open up later in the summer, but I cannot tell if my logic is flawed or if I am just thinking wishfully.

2. I did not network very aggressively my first two years of college (as you may have guessed from my name lol) and am now really hitting the pavement. Is it simply too late to effectively network for SA 2019, and should I concentrate my efforts for FT 2020? I feel as if it may seem aggressive to ask for help for a summer internship, and then ask for help for full time recruiting not even a whole year later. I also feel kind of silly asking for them to push my resume for a program that has been accepting applications for months.

3. On this site, everyone always talks about how nothing will happen if you do not network, and then some people in the comments will be like "actually my friend got like every BB interview without doing it or having relevant experience!" Has anyone who is currently at a bank able to speak to how helpful networking actually is? Is it truly ~everything~, and HR does not even look at your resume unless someone pushes it? Or is it just a way that students with poor GPAs or that go to super non-targets can try to get their foot in the door and for everyone else it certainly helps but is not as critical?