The real stories aren't about elves, or dwarves or wizards. They're about Men. Hobbits, on the other hand, are consistently portrayed as little more than small men, so they get a pass. I'll let hobbits be hobbits without any significant change.
What needs to change to bring about this sword & sorcery, pulpish change to the setting of Middle-earth?
First: Rivendell is not a refuge for the elves. It's a refuge for the Dunedain; the rangers. Elrond does indeed live there, but he's trapped by the arts of the Dunedain of old. He can be consulted, due to his knowledge of history, but he is not necessarily to be trusted. He's like a bitter, untrustworthy Mimir; a dead body hanging from a tree that does not rot and does not truly, completely die.
Lothlorien is indeed perilous. It's Queen will indeed trap any foolish mortals who wander too far under it's eaves in her spells, and if such a mortal ever escapes again, will suffer the fate of Oisín. This assumes that they survive Herne and the Wild Hunt long enough to get caught in Galadriel's spells.
The Lonely Mountain isn't a kingdom in the traditional sense. No mortals know for sure what happens under the mountain, but a few select Masters of Dale have managed to secure for themselves access to wonderful things from Undermountain that they can then use to amass fortunes. Few ask exactly what such access costs them, but it is also true that all of these Masters have, mysteriously, lost their oldest child.
Both Hollin and Dwarrowdelf (or Moria, but I prefer to use the "Mannish" name and minimize somewhat the usage of the Elvish words) are haunted by the memory of the elves and dwarves that used to live there. Not only do spies of the White Wizard haunt the area, and the malevolent spirit of Redhorn the Cruel itself, but passers-by often disappear during the night, their companions left only with the sinister mark of fairy rings where they went to bed.
I'm not sure that I have any real need to do anything with the Blue Mountains and Lindon, since they barely make a cameo as the hobbits pass through on their way to the Grey Havens. But maybe I'll make Lindon a place where mortals live, but mortals who have been touched just a bit by the magic of the elves. Sinister, bizarre; not unlike the men from the cold, dark land of Inganok, from Lovecraft's The Dream-Quest of Unknown Kadath. For that matter; the Blue Mountains can be more like the onyx quarries in the mountains near Kadath—which is itself probably located not far north of the Ice Bay of Forochel.
The other element of Lord of the Rings which has become, in many ways, synonymous with High Fantasy are the orcs. To make them more pulpish, sword & sorcery, I'd turn them into man-apes. Various types, from hugely strong, nearly gorilla-like uruks to the smaller, almost baboon-like soldiers of the Misty Mountains, their appearance would be different, but their role almost identical.