I would go ahead and buy the software, then you get full capabilities and all the time in the world. Go to the help section and read it all and perhaps several times all of the way through. Read it all until you understand it all or all makes sense.
Are you saying that the paid version of RSD has a working and organized help system not available in the trial version? I am reluctant to lay out $200 for a product that will be no more understandable to me than is the trial. Clearly, some kind of instructions MUST be available after looking at the excellent websites many users have posted in that section, but I've not been able to find them.
I cannot help but compare my attempts to learn RSD against my experience with a complex piece of software called IMatch 5, a digital asset management system written by Mario Westphal of photools.com. (If you need to manage images, this is the best manager available) His help system is extensive, specific, and easy to use. He even posted the first draft of help on line about a month before he released his software. The IMatch trial version is not crippled in any way and is good for a month.