Regarding Point 1) -
Where a variable URL needs to be specified, you can use a Virtual Output with 'Save HTTP Reply' with the entry -
/user/common/answer.html
or
/user/common/answer.json
or
/user/common/answer.txt
The 'Command for ON' becomes the URL appended with /<v>.
The Virtual Output can be triggered by any variety of options (pulse generator, time schedule etc.). The 'Save HTTP Reply' then stores the URL response on the Loxone SD card (with some consequences for SD card longevity). You then need to set up a Virtual HTTP Input that polls the internally saved file.
The URL address for the internal file is now -
http://Username:Password@MiniserverIP:Port/dev/fsget/user/common/answer.html
The Virtual HTTP Input command recognition will then need to have the search term set appropriately to find your data field.
Regarding Point 2) -
Text Input to the Miniserver is difficult but not impossible (read ugly work-around). The following link is to a wiki for 'Text Input to Miniserver'.
I've successfully used these two processes ('Virtual Output with Save HTTP Reply' and 'Text Input to Miniserver') to retrieve tokens for device authentication requirements. It gets too unwieldy when the token gets too large, but for small tokens of ~50 characters, authentication is viable using just Miniserver resources.