Cincinnati had two German newspapers, the Cincinnati Volksblat and the Volksfreund. Most Death and Marriage notices will be in those, not the English papers.
The people at the Hamilton County Genealogical Society and the Cincinnati Public Library have been very helpful, and I am in Texas!
The Hamilton County Genealogical Society has many indexes on line, and their little membership fee is worth it for the access to German newspaper indexes.
It is unfortunate that the German's weren't very gossipy people. Many of the Death and Marriage notices don't contain any other family information, but they usually DID notate where in Germany people were born in the Death Notices.
The German church history in Cincinnati is a mess. However, there is a Microfilm of the registers that is not on line. The Cincinnati Public Library also has the Microfilm. You can find this information at the Hamilton County Genealogical Society webpage!