1. Enchained title and protection: Let’s suppose that someone appears as seller in a document or application for registration. However he’s not entitled to sell in accordance with the LR registration books or land books because precisely the registered owner is a different person who has nothing to do with that one. What would your LR response be?
A non-owner can sell the property (technically, the seller assumes the obligation to get the consent of the real owner or to acquire the property).
And, the property status in the land register may no longer be correct, i.e. the proprietor according to the land register is no longer the real proprietor, e.g. the adverse possessor has become the owner of the property, the proprietor has died and the property is inherited by his heirs.
2. Entitlement to alter or modify LR terms. In your LR system, the entries or registrations in the Registration books or land books on the registered properties can be modified?
An entry in the land register can only be altered by another entry in the land register (cf. the passive role of the Land Registrar, IV).
And, the Land Registry and the Cadastre are rather independent one from another. For example, if a house is built on a piece of land, this should be entered in the cadastral documentation, but there is no notice to the Land Registry.
3. Notifications. What sort of notifications for parties or stakeholders do LR offices deal with legally?
In general, the Land Registry does not send notifications: the information is made available in the Land Registry and the parties have to get it themselves.