I love made up cases!!! Do we get more information in this case after we answer your questions? Anyhow, here are my thoughts.
"Female patient unknown transfusion history" I would perform antigen typing for D,C,E,c,e,K,S,s,Fya,Fyb, Jka and Jkb antigens and see if I detect mixed field reactions.
"with mycoplasma pneumoniae" I would like to see the results of direct agglutination test (immediate spin or room temperature) based on this diagnostics using Group O adult cells and cord cells. This antigram only includes IAT where anti-I may not be demonstrable.
"which what exclusions and further testing would you perform" I would also like to see the DAT and Eluate from the cells (especially if I see mixed field reactions in my antigen typing)
"When would you perform a titre ?" If the reaction with Group O adult and cord were both positive (tested at room temperature direct agglutination phase), I would perform titer using Group O adult and Cord cells in parallel to confirm the specificity of reaction seen in room temperature. Reactions greater than 3+.
"If emergency units required with titre greater than 64 what is your protocol ?" I would make sure that transfusion is absolutely necessary by involving medical staffs.
Lastly, I would like to perform ABO/Rh typing, obtain hematology test results (H/H, retic count, any abnormal RBC morphology?), Chemistry results ( Direct/Indirect Bilirubin, Heptoglobin), transfusion history (getting a list of hospitals that the patient has been to and calling each hospital has helped me alot in the past to get this information) on this patient, as it is an essential information in all cases of immunohematology investigation. Also, Drug-induced AIHA maybe a far fetch without further information, but something to be included in the back of my mind.