Raising boys

Boy, what a day! Most all the time I feel fairly confident in how I am raising my daughters, but my son is a whole other experience. How do you raise a boy to be a good human being? Right now it seems too challenging.
Jakey has always been a sensitive boy. He has trouble with strong emotions. It has been a theme throughout his short life. When Glenn's Mom died he didn't seem to acknowledge it the way Vi did. We gave them opportunities to grieve, but he didn't appear to be emotionally mature enough to handle it. So we gave it time. It hasn't been so long really, only 4 months, but we have seen little yet of actual grieving.
Meanwhile Jakey has been the focus of a bully at school already. We intervened and eventually the kid was removed from the situation. The other parent chose to drug their 5 year old (not sure how I feel about that, but that is a whole other post) and for a while all has been well at preschool. Last week though, Jakey behaved quite badly. I was at a conference out of town and so I wrote it off to my absence, but it has happened again today. Today he refused to go to nap (not so horrid in and of itself) and then when a teacher tried to calm him he squeezed her arm very tight to make her stop.
So I am stumped. We thought we came down hard on him last week when he disrupted nap time, but this behavior is totally out of context and obviously last week's discipline did no good.
How do you get through to a boy? How do you make clear to a 5 year old that strong-arming your teacher isnt the appropriate way to deal with feelings? How do you keep them sweet and not loose them in themselves?