@MyCryptoMixer: i've read your reply, and i'm happy you'll be looking into the issues i wrote down
There are some extra remarks i do want to give, and 2 small apologys i need to make:
The apology (1):
I'm a guy that has, at any given time, at least 20 open tabs on my browser. Next to MyCryptoMixer.com, there was a tab open with an exchange i sometimes use that uses the exact same color scheme as your site. The exchange had an option to get notified of deposits by mail, phone, sms, push notification, telegram bot,... They had contact options via mail, ticketing system, facebook, skype, whatsapp, telegram,... I accidentally clicked their tab instead of yours, that's why i wrote the part about not needing so many contact options. It was an honest mistake, and i'll remove this mistake from my review (i'll scratch it).
The apology (2):
After re-reading my initial post, i do come of as quite harsh. I forgot to clearly mention there are loads of good things about your site (layout, security, workflow design,...), but i figure you'll always have tons of people telling you the positive things because they want that payment. That's why i tend to bring up the "bad" things that are fixable instead of focussing on how nice feature "x" is, or how good it is you added header "y", or that you've cleaned up the server signature. Don't read my post as: "this guy thinks my mixer is all bad", but rather as "this guy is bringing up some things i might need to look into to make my service even better"
The extra remarks:
I get that your SEO guy needs those stats, but instead of giving your visitor's data to google, have you tought about Matomo? I've used it's predecessor (piwik) on privacy-centered sites for many times. They give you about the same info as google analytics, but they're just a free (open source) php/mysql script that runs on your own server, keeping all your visitor's info with you (and there even is an anonimizing function included).
About cloudflare: i do get why people use cloudflare. Don't get me wrong, they do a great job and for any site where privacy isn't so very important, i wouldn't mind seeing the use of cloudflare's cdn, ssl certificates, dns services,... I realise you're defenately not the only one using cloudflare for a mixer, but every time i see a mixer using cloudflare, i raise exactly this point. What people seem to miss is that, eventough it looks like you're using a secure connection, cloudflare actually acts like a MITM. This means the data is encrypted between your browser and cloudflare with cloudflare's cert, cloudflare DECRYPTS the data (they now know everything, including the deposit address, the letter of guarantee, the withdrawal address, the user's ip, browser fingerprint, timestamp,..). They have ALL tools in hand to completely de-anonimise the mixing session. Sure, they re-encrypt this data with your cert before they foreward the package to your server, but nothing is stopping them from sharing the complete de-anonimised mixing session with the CIA, FBI, ATF, DOD,...
I get you need a WAF, i get you need DDOS protection, i get that it's only the clearnet... But a lot of your users won't know what tor is, they just want privacy and they're looking at you to provide them with this privacy. The very least you should do (in my opinion) is print a very big, bold warning on the clearnet version telling your users that, eventough their coins will be safe from bad guys, their session *might* be monitored by law enforcement unless they use the tor version.
There are a couple of hosts that offer Ddos protected dedicated servers. If you combine this with a decent setup and a letsencrypt certificate, you're much safer than you are now (security wise).
Last but not least: i messed up some of the header recommandations. I have a couple of secure setups i'm involved with (but not that many) and i have a messy checklist to verify if everything is more or less correct. Sometimes this checklist is not up-to-date and headers that are no longer best practices are still on the list. You've given me something to think about, and if you are correct, i'll remove those headers both from the services i'm involved with and my checklist... Thanks
BTW, i'll send you a PM with an address, so i can review the rest of your setup