I think at this point since you're frustrated anyway it's worth making the leap to the cot. Yes, it may be tough for a few days but then it will be done. If you keep on as you are I think you'll be frustrated with the rocking, etc and then you'll still have the frustration of getting him to sleep in the cot. This way, it's all over sooner.
I would go with the A time that you think is best (or follow his cues), do whatever he likes for WD and put him in the cot. There may be rolling and not a lot of sleep at first but sometimes expecting that makes it easier to handle, yk? Leave him be if he's just playing or fussing and only intervene if he really needs you. I wouldn't wake him from any naps for now either. Use EBT to recover if a day goes sideways.