Hi,it should not fail for # in the url.Do you see any console log on browser while you do the save of dialog

Connected asset is the only option that I can think of

Aem cloud support the same Asset structure that are on aem 6.5.however you need to keep the scope of work in mind at this time only when you move to cloud as there are some feature that are supported on on-premise and AMS but not available on cloud like smart translation search, metadata write back ...

Check this onehttps://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/extending-file-name-validation-in-aem-assets/td-p/298210

Since drop-down value coming from json are not visible in metadata form location setting the default option as select twill not work OOTB with values coming from json.if you still want to achieve this then you need to do your custom implementation. Check this for reference https://experienceleagueco...

Do you see any error on aem error log for the time of expiry?are you able to login on aem publisher and verify that asset is still present in Dam folder?are you logged in as administrator user on sandbox?

Why don’t you run a query to filter the node based on sling:resourceType to be your component path for your page.once you get the reference of all of your component node you can iterate them any way as you want 

See mock fragment data section on http://www.java2s.com/example/java-src/pkg/com/adobe/cq/wcm/core/components/extension/contentfragment/internal/models/v1/contentfragmentimpltest-e684b.html

As per your explanation you are trying to consume assets from aem author on 3rd party application which won’t be recommended if you have publisher and dispatcher setup for your environment.With those authentication in place how are you accessing the image via image source.best way is to use the asse...

What do you see in error.log?