Thanks for your interest in Aspose.Words.
1. Most likely you are using old version of Aspose.Words. In the latest version there is no Aspose logo in the viewer. Moreover, you can specify your own logo (See LogoImageBytes):
You can download the latest version of Aspose.Words from here:
2. Full screen mode might not work in browsers. This is not a bug but security restrictions of SWF plagins in browsers.