Module development and code questions

I develop in PhpStorm and it is complaining with the message:

Expected parameter of type \Drupal\node\Entity\Node, \Drupal\node\NodeInterface provided

Does this suggest I'm doing something wrong? In my class I have something like the following...

Dear Drupal Community,

I am getting following error code:

Warning: Creating default object from empty value in adaptivetheme_preprocess_html() ( line 14 of / urs / ww / users / immobigg / drupal 7 / sites / all / themes / adaptivetheme / inc / template, process. inc)

1.) Can anybody tell me how to solve it - where do I have to change or delete something?

I created my first sandbox project today. By now, I have:

I have a page (form) that I've created a twig template for, it's called `form--edit-communication-method-form.html.twig`, it loads in my actual form items as well as some other markup to polish everything up. However, now I need to present this form in a modal, and I'm attempting to do so by loading the form like so

I want to have an ID in my URL and the controller of my module should take the ID from the URL and display it. If the ID is changed in the browser and the side is reloaded, the page should print out the new ID. My problem is, that I can't get the ID out of the URL.

Example: /node/31?id=930bcae8-f8e5-491f-84fc-cdf104ca7e40

I have tried to following lines of code, to get the id and print it out:

'text' => \Drupal::request()->query->all(), <- prints out nothing

I am attempting to use a modal on a particular page using the following link to get there

<a class="use-ajax" data-dialog-type="modal" href="/my-modal-page">

However, there is some default modal behaviors I would like to disable: