1. I have let my property to a tenant on a three year term. There are still more than 2 years remaining in the term. However, I note that the rental value of neighbouring properties has risen significantly. Can I terminate the tenancy with the existing tenant and let the property out for a better rent?

A party to a contract is bound by the terms of that contract. Therefore, unless a tenancy document contains a break clause that allows the landlord to terminate the tenancy before the expiry of its term, or there is mutual agreement for an early termination, the landlord is bound by the tenancy document and cannot unilaterally terminate the tenancy with the existing tenant.