Module development and code questions

Hello,
I want to make a cultural event management website with an offline version synchronized with the online version.
Authenticated users of the site must be able to use it even without an internet connection from their mobilephone (possibility to install a mini web server on the phone).
Changes made during the offline period must be synchronized with the base of the main site when an internet connection is available (synchronization in both directions according to rules established in advance).
I am on drupal 8.

On my site, I have several types of store.

I want to customize the "Add to Cart" button of the "Online" store products.

I created a custom module for Drupal 8.6 and Drupal Commerce 2.11

Currently there are errors in my code. All products in any type of store are personalized.

How to limit the code only to the current store of type "online" ?

https://docs.drupalcommerce.org/commerce2/developer-guide/stores/create-...

I recently created a new module on drupal.org, and I do not appear as maintainer (and the "view all committers" page is wrong). How could this be corrected?

I have a controller which sits in front of a Form which checks the user's IP and does the following:

Hello, I'm editing a Drupal module, and in the module there are some hooks created(in [module name].api.php file). I invoke the hook inside the same module. So I edited one of the hooks to see some results, but it seems that for drupal the hooks is not edited, since I'm having the same result as before. I cleaned cache but still same result.

So can you say me how can I update/refresh the hook or the hook file?

Hi Team, 

Is there any way to update the success message appearing after deleting block?

Message coming now : "The custom block {{Block Label}} has been deleted.

I tried to look into this and found this message in generating from Drupal\Core\Entity\EntityDeleteFormTrait getDeletionMessage(), not sure how to override this function?

Thanks!