coach issue

Ive had four parents complain about one of my captians. Not really a bullying issue but a kid that is putting down the other kids. Always being negative, bossy type attitude. Coaches kid (btw), so I pull the kid aside and tell him Ive had several complaints about his attitude twards the other players and that he needs to be more positive and to stop the negative stuff. I tell him this not sternly but as "hey I know your trying but its coming across wrong to the other players". Well his dad is out of town on business trip so he wasnt there when I talked with his son. I get a phone call that night from the dad. Basically saying its b.s. He doesnt believe his son would do such a thing. I tell him four different parents complained so I doubt they are all lying. Also our coaches have seen some questionable character issues. He demands to know who the parents are. I tell him "no, that isnt the issue" I tell him, its over now lets not make a big deal of this. This guy literally thinks his kid walks on water, he does not have a real clear view of his kid. So I show up to practice today and one of my coaches tell me that the dad called him. He is mad and he is thinking of pulling his kid off the team. He also calls my o-line coach, whom they are good friends and complains. He tells the assistants that he is thinking of pulling his kid off the team. This is a threat, he would not pull his kid off the team.There was some definate tension between me and the o-line coach today. We have started working on some spread offense with my best athlete at qb and the coaches kid from qb to the blocking rb (he is not the best athlete) Everyone was pretty excited about this. The o is looking good and its going to give a different look to the opposing team. So now today the o-line coach doesnt like the spread and wants to stay exclusively with our base o. I think this is coming from the dad because his son is not the qb in this package. What would you do with a coach that you feel is causing issues. Would you have a talk with him or just boot him from the team. I dont care if he takes his kid, I dont care if my other coach who has a son that is the best athlete in the leauge pulled his son off my team. Its youth football. I want to win like everyone else but it is not my end all be all. This is just one incident. He also has another son on my team and he wants him to be a two way starter. Last week I finally told him its not going to happen. We have to treat all the players failry and we will not play daddy ball. His son is barely above a MPP but he wants to start him on offense and defense. Not going to happen while Im the HC. This guy is draining my joy of coaching. If I kick him off coaching staff, will cause big issue with O line coach. Feel kind of stuck, give me your opinons, I need them.