Restraining order AND/OR removing unauthorised sub-letter

Hello, I rent out an ancillary dwelling next to my home. I am having some serious problems with my tenant's boyfriend and need some advice on whether I can have him removed as an unauthorised sub-letter, or possibly get a restraining order to force him to leave. The situation is a little messy so please bear with me. 

The tenant has signed a 2 year lease which she is currently half way through. Her boyfriend has lived with her since the start of the tenancy, but he is not on the lease agreement. Over the past year I have been living in increasing fear due to the boyfriend's behaviour. He has fits of rage with shouting for up to an hour, he has punched a hole in a wall in the flat, and has made a threat towards the tenant to "smack her in the head". I have a written log and recordings of the yelling, and also have the threat recorded on video, and I have a photo of the punch hole which I took during an inspection. I intend on taking this evidence to the police but I am hoping to have the boyfriend removed first, or at the same time, because he will certainly know it was me who reported him and I don't want him to direct his anger towards me while I'm living right next to him.

I spoke to a real-estate agent and a lawyer who both told me that eviction is very difficult - and even if my case was strong enough, it would require me to serve them with multiple lease breach notices which I am again worried will be continuously provoking him. However I was advised that because the boyfriend is not on the lease, it may count as sub-letting, which is specifically disallowed in our lease agreement. I have been getting conflicting advice on whether or not I have grounds to have the boyfriend removed under this rule. The real estate agent who had 20yrs of experience was adamant that I could submit just 1 breach of lease notice regarding this clause, which would require him to leave in 14 days. However I also did a call with the Tasmanian Consumer, Building and Occupational Services, and was advised that I cannot restrict who the tenant allows into the flat. Hoping to get some clarity around this because I don't know who is correct. For reference, the sub-letting clause in the lease agreement is as follows:

"10. Subletting 

a. The tenant agrees not to sublet the property or any part of the property 

without the prior written consent of the landlord. 

b. The landlord agrees not to withhold consent unreasonably. "

Since the boyfriend has been living there from day 1, and I have been treating him as a tenant, I worry that in doing so I have "implicitly" approved of him as a sub-letter even without formal written consent.

Another avenue I became aware of when seeking advice, was to try to get a restraining order against the boyfriend which would have the same effect in forcing him to leave the property. I don't know if this is worth pursuing since he hasn't made any direct threats towards me, only to his girlfriend, but the from does include a section to get the order due to property destruction, and I wonder if him punching a hole in the wall gives me any grounds for that.

Thank you in advance for any and all advice for my situation 🙏