Guidance on Rivers State tenancy practice for a landlord's rental platform

Good day, esteemed members. I am a software developer building a rental management platform for a landlord in Rivers State. Tenants pay the landlord's bank account directly, and the platform does not hold any money. Before I finalise certain features, I would be grateful for the guidance of any practitioner familiar with Rivers State tenancy law. Please feel free to answer only the questions within your experience, and kindly point out where you are unsure. 1. What notice should a landlord give before a yearly or fixed-term tenancy ends, and in what form? We plan courtesy reminders at three months, one month and on the expiry date. Is anything further required? 2. If a tenant remains after expiry, may the landlord change the padlock, or must he proceed through the courts? What is the correct process in Rivers State? 3. If a tenant has paid and the unit is not ready for handover, or the tenant cancels, what refund is required and what may lawfully be retained? 4. Are there any limits on advance rent or caution fees in Rivers State? 5. Does a tenancy agreement require stamping, and how is it done? 6. May a landlord require a tenant's NIN, ID type and next-of-kin details, if a privacy notice states the purpose? Would the platform need NDPC registration? 7. How long may tenant records be kept after a tenancy ends? I will gladly cite any law or authority you mention and would appreciate your corrections. Thank you very much for your time and guidance. Kind regards