Hi CK, On the first point it sounds like you are missing an override for the image class when embedding in an article. You need to override the content/view/embed.tpl file for the class image in your new design. It might work to just copy the one from the admin site design. So you have something like this in your override.ini.append:
where image_class_id is the id of the class in you installation.
Secondly, to submit a form you need to add to your site.ini.append a setting to say that you can submit forms on your site. this should read like this:
[FormProcessSettings]
# Whether the form module is allowed or not
# The form is by design insecure so don't enable unless you know
# what you are doing. Module=enabled
This is copied straight out of the standard site.ini file and the module is set to enabled.