The field mapping object manipulation you ask about is a pretty heavy lift of Python programming for beginners. If you are still up to it, here's the basic idea. "fms" is the FieldMappings object you can use with FeatureClassToFeatureClass.
Even with the complexity of the FieldMappings object methods and properties, this does still seem easier to me than dinking with NumPy arrays and such to simply change the data type of your fields... assuming the structure of your 100 tables are identical.
fc = listFCs[0]
fms = arcpy.FieldMappings()
fms.addTable(fc)
nfields = len(arcpy.ListFields(fc))
# skip fields 0,1 (OID, Shape), next 10, and the last two
for fi in range(2 + 10, nfields - 2):
fmap = fms.getFieldMap(fi)
ofield = fmap.outputField
ofield.type = "Double" # change from String to Double
fmap.outputField = oField
fms.replaceFieldMap(fi, fmap)
for fc in listFCs:
outName = inFeatures
arcpy.FeatureClassToFeatureClass_conversion(inFeatures, outLocation, outName, fms)
FieldMappings—Help | ArcGIS for Desktop