Why don't you ask Weblogic questions in the Weblogic forums? https://forums.oracle.com/forums/category.jspa?categoryID=193
If you startup the server with a simple webapp deployed to it you should be able to see in the server log which implementation of JSF is there. A simple text search for "Mojarra" should already tell you if it is used or not. A simple google query for "weblogic 10.3 mojarra" seems to indicate it is in fact Mojarra for both JSF 1.2 and 2.0.