What should we do if we spot problems, wear and tear, or damage inflicted by the previous occupants?
Ideally this should have been identified upon arrival and with the completion of the Inventory / Schedule of Condition. However, if anything was missed or comes to light after the tenancy has begun, it is best to contact your landlord both by telephone and in writing to inform him/her of the problem. Written notification is best so all parties are aware of the problem and it is better for confirming the date upon which the problem was identified.
Damages - what should we do if we have broken something in our house?
You should inform the landlord immediately. Depending upon your landlord, the object, and the degree of damage, you may be able to repair it or come to an agreement regarding its replacement. If the damage was inflicted by your guests then the landlord would ordinarily ask you, the tenants, to pay for its repair / replacement.
Damages - what should we do if something in the house is defective / has worn out?
If something in the house appears to be defective, worn-out, or beyond effective use, then you should inform your landlord as soon as possible. Once again, written notice is usually the best way of letting your landlord know. They will need to be notified as they may not be aware of the issue. If it has indeed worn out or is defective then the landlord would usually have to pay for the replacement.