Can you verify your servlet here and see if your servlet is getting registered for the given resourceType : http://localhost:4502/system/console/servletresolver?url=yourResourceType&method=GET    

You can add some empty text in your component's jsp to have it some height when dropped <p data-emptytext="Author here" class="cq-placeholder"></p>  

Could you check the npm and node version configured in your pom.xml and confirm if install version and required versions are the same?   If not, try to build with with below parameters  -Dnode.version=v18.9.0 -Dnpm.version=8.19.2    

yes, you can add it to file  'head.resources.html', residing under the page component. By default, it takes the path of clientlib resource folder as @arunpatidar has already mentioned.   

It seems the component group you have added in policy and the group of component that you have created is different.   allowed one:  WKND SITES PROJECT - CONTENT (It is not listing the byline component) desired component's group: WKND Sites Project - Content   Can you change the casing of the group ...

you'll have to add support from backend as well for both old and new property. if new is not there then put a check if old one is there and show the content based on that 

you can make your text fields hidden and when the dialog will be loaded you can read their previously authored data; if any value is authored,  programmatically click the multifield add button in new multi fields and populate it.   here is what we did for a similar scenario:   (function ($, Coral) {...

you can use the component conversion tool from the AEM modernization suit as well. Here is how to use it: https://opensource.adobe.com/aem-modernize-tools/pages/component/usage.html   you won't need to provide the page paths it will fetch it based on the component's resource type.  

As mentioned here  https://developer.adobe.com/experience-manager/reference-materials/6-5/granite-ui/api/jcr_root/libs/...    heading resource supports just level and text Only form fields that extend https://developer.adobe.com/experience-manager/reference-materials/6-5/granite-ui/api/jcr_root/lib...

  You can add  lowerOperation property to include the 1:05 as well    Can you check the query you have shared? doesn't seem proper.