Yes, the border of the shape is stroked, so you can set a stroke color and the stroke color can have a different opacity.

If you install current versions of PDF24, then all these mentioned functions should be available. Are you sure, that you have installed a recent PDF24 Creator version?

Where is the data stored when invoices or individual blocks are saved? With the online tool, all data is stored in a database. The database itself is located locally on your computer in your web browser's...

You have to use: "all/profileid" Information is here: https://creator.pdf24.org/manual/11/#1114-apply-a-profile-to-input-files 

Please send a screenshot to forum@pdf24.org so I can see what you mean.

Hi, I think you should read this: https://creator.pdf24.org/manual/11/#1115-join-input-files-and-create-an-output-pdf-file

Hi, just open the "Convert PDF To ..."  function. There you can select the text out format.

Signing PDF fiels with a certificate is possible via the profiles section, there are options where you can also select a certificate. Such a signature just digitally sings but does not add a visual representation...