Clearing cache should not be detrimental. However, as large as your cache is you may see significant improvement on performance when you do.
Don't delete that file, use the Clear Cache dialog in ArcMap
The cache file in the first link is over 18 months old and must be from a previous version of ArcMap
Try renaming it first. Then run ArcMap, if nothing detrimental happens that this is probably the case. You should be able to delete it. If it does cause issues then you can restore it from the Trash
If emptying the cache did nothing, then it may be a remnant as suggested. Try not to delete folders using your operating system, rename as suggested would be safest until you are sure your current version works, then delete