"Is Lord of the Rings difficult to read?"
I wouldn't say it was easy, but I don't think it is any more difficult than the play that you mentioned.
Here is a fairly random sample:
'Dark tidings', said Theoden,'yet not all unguessed. But say to Denethor that even if Rohan itsel felt no peril, still we should come to his aid. But we have suffered much loss in our battles with Saruman the traitor, and we must still think of our frontier to the nort and east, as his own tidings make clear. So great a power as the Dark Lord seems now to wield might well contain us in battle before the City and yet strike with great force across the River away beyond the Gate of Kings.'
Note some of the vocabulary:
"tidings" rather than "news"
"peril" rather than "danger"
"aid" rather than "help"
"frontier" rather than "border".
Also words like "wield" and "beyond", and short powerful words like "but, "yet" and "still" rather than "however" or "nevertheless", "think of" rather than "consider", etc.
Then there are words like "unguessed" which compresses what could be a whole phrase into a single word. Perhaps somewhat reminiscent of a line in the Scottish play you mentioned: "Or else my sword with an unbattered edge I sheath again undeeded".
It is probably good for increasing your vocabulary, though you should, of course, remember that much of the language is only suitable for conversations with wizards, elves, and the like, and is not suitable for everyday use, just as you would probably avoid phrases like "gekeilt in drangvoll fürchterlicher Enge" in everyday speech! (:-)