There is nothing unusual about SQL using most of the memory on the server, that's how it's designed to work. You need to ensure that you have set max server memory to a sensible value based on the memory in the server and whatever else is running on the server.
110GB on a 128 GB server should be fine, but if you think it's using too much memory, drop max server memory down slightly.
Not doing CheckDB is not an option, that was a silly suggestion from whoever posted that MSDN post.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability