hi!
1- unfortunately NOT (big mistake so far imo)
2-i think not, but i don’t have the machine here now 
3-not, the different lenght is adjusted with p.locks, because like you say are one shot samples controlled by adsr and sample duration
4-no
5-i see Rytm easier than octatrack, anyway i think both are fast workflow machines, maybe learning curve in octatrack is a bit more longer, but not something really complex