You are in the right direction about how you can fine-tune Lucene.NET with better control about how it should behave. Please see Lucene stemming where you have example how to change analyzers for index and searching.
Note: Litium uses Lucene.Net 3.0.3 that will match Java version of Lucene 3.0.3 and your reference above is for Java Lucene 7.5.0 so it can be some differences in existing functionality.