A study of radiative τ pair production,e + e −→τ+τ−γ ande + e −→τ+τ−γγ, is presented. The observed events agree with QED predictions of order α3 and α4. Excited τ′s have been searched for and lower limits on single and pair production are obtained. For QED-like coupling the τ* mass is limited to values greater than 40 GeV (95% CL). A search for unstable charged scalars (S ±) decaying into τ, e.g. charged Higgs, technipions or the supersymmetric partners of τ′s, yields no evidence for such particles. Assuming a branching fraction ofB(S→τν)=1,S masses up to 18.7 GeV are excluded with 95% CL.