Can I evict my ex boyfriend from the home we are buying on land contract, based on abuse

You could either get a restraining order based on the abuse (which, in most States, keeps him off the property for a period but not necessarily forever) or you can begin eviction proceedings based on your State's laws.

If he is on the deed and mortgage ( land contract) you can not evict him.
If he is abusing you, and you have proof, then a order of protection wii be needed

No you cannot evict him if he is on the contract, loan or mortgage.

A restraining order is a better tactic.