Ηallo to everybody!

I work as an RnD analyst for Inhalers testing. I would like to develop a method for UPLC-MS/MS (Waters acquity) for the detection, seperation and quantitation of 2 enantiomeric impurities (Imp.G and Imp.H CAS:1508-46-9 of Tiotropium Bromide(API)) in a final drug product. I do not have matrix problems since my analytes are diluted in my mobile phase (containing lactose excipient, ACN, buffer, API, impuritis). Could you please suggest me:
1) What column (chiral, uplc or not) to use as a first step?
If I use chiral column do I have to add an organic modifier for derivatization and if yes what kind?
2) I will try both ESI and APCI for ionization in order to conclude which source and polarity leads to better sensitivity and selectivity (I guess that ESI (+) is ideal for a wide range of analytes)
3) Is is possible to seperate these 2 impurities without using a chiral column? maybe each one gives different ratios m/z after fragmentation? However, I know that for the quantition we use the most abundant ion and we confirm with the confirmation ion
4) One general question: Can I use HPLC columns (250x4.6, 5μm) with a UPLC pump? I think yes but i woull appreciate your opinion too.

Thank you!