Its NOT clear from your post if there is a custody order in place or what--and it could make a major difference .
(If there is NO order thare are some who suggest move first, qualify as resident in new state , then sort it out--this has some risks and some merits--at least discuss it with counsel)
I think it important that you NOT share iANY nformation about your plans with Dad, friends , enemies, or family except on a legal need to know basis--discuss it with counsel only .
If there is an order, the lack of job locally and the assured job via transfer via your current employer very much sounds like a reason you can articulate to be in childs better interest to have a parent who is able to economically provide for child--but you bear burden to state it in clear language that counts to court, and I sugggest you focus on benefit to child--and its OK to state downside of no job = peril to child as well. Be prepared to address that you have made a diligent search for jobs locally and found zippo, if thats true.
Moving to be with new BF is not in childs benefit as such--and I'd not suggest you get into same --it opens up wrong issues.
If Dad is not paying CS--why not? If there is no order for same--I suggest you go get an order ASAP. (Discuss potential jurisdictional and logistical issues with counsel up front--its possible you might be better off to use new location--but ask first!)
Moving and CS are not supposed to be linked...but it happens as a practical view.
Dad probably has rights to visit his child or can seek same by order .
If there is an order, you probably need to address as the move away party how to implement a reasonable visitation with child and you may need to pick up a lot of the visitation costs.
Yes, that means you could be stuck to pay for his visits at same time he stiffs you/child on CS--so be careful how you address this area.