I'm really struggling with this, have made little progress and not really enjoying it.
13a Augustus was one heading off moderate men (7).
Looks like 'emperor', don't get the 'moderate men'.
41a You and your endless anniversaries finally must stop - with this one?
Thousandth?
32d Bird soaring over cape, then height almost halved (3,4)
Coal tit? Cannot begin to see why.