heh. I upgraded and then went through the logs to fix everything -

  1. I'm running a separate php-fpm socket for my tempdeals project than for everything else, so had to recreate that.
  2. One plugin had break points inside loops, something which php 5 doesn't care for, but php 7 definitely throws an error for. The plugin maker had updated it late last year for php 7, but I cannot accept his changes any more because I've got some custom code changes to his plugin which I cannot overwrite. So I had to go in and remove the break commands.
  3. phpMyAdmin needed the php-mbstring extension, so had to go and install that specifically for php 7
  4. One plugin needed php-curl to be installed

Other than that, things seem to be running fine. I'll wait for things to break before going in and fixing them again.

This also allows me to try the default settings for php-fpm again. I was getting ridiculous timeouts a long time ago and some SO and AskUbuntu answers led me to change the fpm type from dynamic to static and to reduce the amount of RAM and processes allowed to it, but I'll see how well the defaults work now.