Covenants

We own a downstairs flat with a Newcastle lease (also known as flip/flop).

The deeds state:

The Leesee hereby covenants with the Lessor as follows:-

to keep the Demised Premises in good tenantable repair and condition throughtout the term and if necessary to rebuild any parts that require to be rebuilt and not to make any structual additions or alterations except with the consent in writing of the Lessor (such consent should not be reasonably withheld) and to yield up the same in such repair and condition on the determination of the term hereby granted

If all the copper pipework and hot water storage cylinder have been removed, can we force the leaseholder to replace these items as it is not in good tenantable repair and condition?

The deeds also say:

To ensure that the Demised Premises are insured at all times throughout the term in the joint names of the Lessor and the Lessee (and any mortgagee) against loss or damage by fire flood and other risks.......
Does this mean we have to insure our flat with the same company as the owner of the upstairs flat?

TIA

Mr/MrsLandlord