What are some ways to address inaccessibility of to-be-learned material for research?
Sorry, but there isn't an easy path through the research jungle. You just have to hack away at the obstacles as you find them. It is actually much easier now, with internet resources and electronic publication than it was, say 50 years ago. But inaccessibility of resources and difficult of interpretation has faced every researcher. 

Of course, some obstacles don't face every researcher. Doctoral students in the past normally needed a reading knowledge of at least three languages. That requirement made more papers available. My own dissertation advisor (mathematics) wrote, over the years, in five languages himself (Czech, Russian, Polish, French, and English). That language ability made some things easier. 

Every student needs the experience of not understanding a paper and working back through the references until the get a feel for what is being said. 

Your "blocks" may be different from my blocks, but neither of us is free of the need to just slog it out at times. 

But an even bigger need is that a researcher needs to develop insight into the very fundamental nature of a field. The resources aren't enough to guarantee that you will get this, and without it, you won't be able to extend what you find in the existing record. As you hack away at the obstacles in the jungle you also need a vision of your direction and where it might lead you if you keep hacking.