Module development and code questions

I have created a compound field with 2 subfields (title, body). Now I need to add another subfield (Footer) to the same compound field.

Though I have added the new field definition in all required places (propertyDefinition,schema,formElement), field is not getting created in the table. How to achieve this? Kindly help me on this.

I've tried aggregation, it works and it's comfortable. I have a greater and more complex need.
In the views I have 2 content types. Each with a numeric field.
The aggregation should display the total by content type and then calculate the difference between the 2 amounts.

I would like to make it programmatically. Can you route me to suggesting what to read?

Hi,

I have moved a correctly functioning Drupal 7 website to a subdomain, and my webform is no longer working fully. Here is a summary of the problem:

Hey there!

Now, before anybody says 'theres already a module for that', let me point out that what I am trying to build is a special use case that doesn't quite fit into all the other modules I can piece together to make work, so let me explain.

I am working on a management system where users can store addresses in a personal address book. Simple enough, right? 

Sure, but to go beyond that, there is other functionality that I need to build, and was wondering how best to approach it. 

I need to switch blocks in some region using ajax, I tried a custom route with a controller

$.ajax({
        url: Drupal.url('ajax/my-custom-route')

And in controller tried render blocks: