Hi Dennis,

basically nothing has changed in the media screen to select image for logo, it's the default Joomla control as in previous version. If you hit 'Insert' and nothing happens it sounds like a javascript issue.

About the look of the control panel it seems weird, the icons should be larger and blue colored as in the demo area: http://demo.storejextensions.org/responsivizer/administrator
try to login using username: demouser password: demouser

but this could be a caching problem in the browser.

John