Well, purchase window is just not comfortable, could be A/B/C/D/E with A for FirstStrike value, B for normal attack, C for FirstStrike value defense, D for normal defense and E for movement, maybe the number of rounds in brackets like : 2(1)/3/3(2)/4/1 but that looks at bit much info, colour could be used maybe.
Any text popup beeing configurable would be good, probably needs to be per unit, maybe within xml under unit attachments.
For engine casualties selection and AI it is not so easy to set. 2 attackers with 3, one FS, one normal and 2 defenders with the same values, for example is hard to judge, as it really depends on the hits your opponent scores. If both FS miss, but you get a hit in normal round, you sure want to keep your FS unit and the same situation when a FS unit scores a hit, but when the FS values are lower, say 1 or 2 with 6 sided dice, it is much harder to tell and more gambling, while I would say a FS unit with 2 is still better than a normal unit with 3...