The few games that have been released officially on consoles have been rated T, due to various things like the depiction of alcohol and smoking, and having the final boss fight literally take place in the middle of a giant lake of flaming blood. In general though I think Touhou is pretty family friendly, if not necessarily geared towards children. It's nothing that kids weren't raised on in the 90s and 2000s, and with a few minor exceptions the series is as chaste as it comes with fanservice. About the only thing I think people might find objectionable is the strong implication that Reimu and Marisa were underage drinkers in the older games, but that's something you just have to take or leave.