We applied to YCW18 and wanted something that aggregated news about it and gave us the opportunity to chat with other people who have applied. If you would login, you would see there is quite some activity. I'm sure there are many areas of improvement to be found.
To come back to your list of critiques: 1) We are not affiliated with YC, nor do we claim to be. @vinaipay already pointed out your misunderstanding about the company's domain owner. 2) Registration is a standard Laravel component that hashes your password. 3) We are loading external images from rss feeds which are not over https. Maybe that is what you are referring to.
Things we will do: 1) We are putting a disclaimer on the website that we are not affiliated with YC 2) When and if this side project becomes something more than a side project, we will invest time and money to store the images and send them to you over https
Note: I was tempted to write this entire post in all caps :)
Have a great day!