I agree with dant, run with what you have. that said you aren't going to get forfeiture unless she is monumentally stupid and refuses to do what the court will inevitably tell her to do - insure as required or else.
As to the other breaches you are going to have to send a letter before action so have the same solicitor do that.
The claim to a lease extension is a statutory right but would likely waive your right to enforce the breach by section 146, at least, if you acted on her request.
Once a section 146 is served then the claim will end up before the court to decide along with the breach.
what I do see here is to say firstly dont conflate the issues with mutual non cooperation,. but secondly a lease extension and cooperation is also at basis for a solution- insure and repair and I do a deal on the extension.
Realistically the process is not about getting her out and possession as it will go to the ends of the earth to fix the issues. An LVT may determine a breach has occurred, but frankly the Court has the tough decision of deciding who and if they go.
Based on the information posted, I offer my thoughts.Any action you then take is your liability. While commending individual effort, there is no substitute for a thorough review of documents and facts by paid for professional advisers. More ramblings atleaseholdpropertymanager.blogspot.com