1. Yes. Flap 45 is the normal landing config.
2. I don't remember any special limitations.
3. So no.
4. Of course.
5. Other alternative landing config is Flap 22. Only used in LV Ops.
It would appear - as I see it - that there was no vilolation of SOP or limitations.
In the adsence of an atmospheric issue (Windshear, thermal, etc) , it seems that this can be chaulked up to an "Ooops" on the crews behalf.
I'll wait over here while the jury deliberates.
ps: Can I assume that the LV ops requirement of flaps 22 is to satisfy go-around climb performance?