Good grief, but this one has been thorny!
I am now reluctantly prepared to concede defeat with
10ac) Senator and heretic in some classical verse (8)
for which I seem to have ?E?A?I?E? I can only see PELAGIUS, who was certainly a heretic, but I cannot square the classical verse bit and don't think he was a senator either...
Yes!!
For this relief much thanks, mac44. I am still unsure as to Franzen's volume, but assume LITER + O to give LOITER, by the way. But the sun is shining....