Also do realize that this code creates hanging sessions that you want to avoid

Do you see anything related in the error.log?

There is no need to include global.jsp in HTL files.This is required for JSP files

when using non-String types make sure to use the correct data-type.Example here for the service-ranking and using :Integerhttps://github.com/heervisscher/htl-examples/blob/master/core/src/main/java/com/adobe/examples/htl/core/bindings/CustomBindingProvider.java

I am not aware that the Felix annotations are deprecated in AEM6.3.To your question on @SlingFilter, this is same like @SlingServletThere isn't an equivalent you can use. You need to specify the properties like in this sample for a servlet.https://github.com/heervisscher/htl-examples/blob/master/cor...

You can have multiple ways here, but you can of course store the clientlibs you want to use also at jcr:content level.Then using the inheritedPageProperties you can request the property.This way you can override the setting at each level.

Here a screenshot from We.Retail on aem6.3 (edit template -> page design)

When using the template editor you can also specify the clientlibs there.Those can then be specified to switch or implement a new design.

get() can be used when you pass in for example a parameter.For the use-cases to get a property you need to access it via getProperties().Where have you seen that in the documentation?