1. Which is the essential for a valid lease?
It is exclusive possession. If th possession is not exclusive it is a licence. Rent is not essential. People whho do not pay rent have been found to have leases. A fixed term is not necessary it could be a pperiodic tenancy.
2. If a lease has an uncertain term but rent it paid regularly will this be a valid lease?
It is still a valid lease as a periodic one. The court mayy fill in the blanks if needs be. They will go by the norm.
3. Considering your answer to question is this a legal lease?
No it is equitable for lack of formality.
4. Which of the leases needs to be substantively registerd to be legal on creation?
A lease of over seven years. Only OVER this time – not xeactly seven years . That is in tje Land Registration Act 2002.
5. What are the requirements of a valid equitaable lease?
It must be specifically enforceable as a contract.