Dear Daniel,
1
The Javascript version should work yes. But you cannot use the jQuery(document).ready(function(){function.
Because your Lay Theme website is a "Single Page" JavaScript application you cannot just use jQuery(document).ready(…) to execute your js because the ready event only fires once when the website loads the first time.
You need to use window.laytheme.on("newpage", function(layoutObj, type, obj){ });.
You can find a detailed documentation about this here:
http://laytheme.com/documentation.html#custom-javascript
2
The append solution might work. You need to test it with the new way of calling jQuery I mentioned above.
Another way I would try is to get the image url and place it via jQuery into an image box which is outside of the Gridder-Module.
Since this is not a default feature – we need to find a workaround like that.
3
I answered that above I think :-)
All the best and let me know if you have further questions!
Marius