1. What are the essential elements a claimant for an interest in land has to show to successfully claim an interest in land arising from a promissory estoppel?
2. A lease is said to operate both as a contract between the original parties, and as a leasehold interest in land binding on the successors in title to both the landlord and the tenant. What significant legal impact will that duality of legal effect have on the original tenant (and any original guarantors) if the original tenant assigns or transfer that lease and the assignee later defaults, and why will that impact occur?

Answers need to be relevant to NSW.