I have two questions: First, I have been using DVD Studio Pro and have found certain issues with the program that I haven't gotten around. Is DVD Studio Pro the top of the line authoring program for Professionals or is there something else out there that is better?
Lastly I would like to encrypt all of my DVDs in-house. What kind of program/machines do I need to have in order to make this happen. Will I need to be able to create DLT masters or is there another way around that?
Depends on what you mean by top of the line? There are other tools like scenarist which require you to know the DVD spec to author a disc. Most studio discs are authored with these systems. DVDSP is an abstraction layer tool which hides the mundane coding required.
DVDSP is more than good enough to author most titles but no tool will allow disc encryption in house - only set the flags which tells a replicator to apply CSS.