Minutopia - isnt wear and tear the LL responsibility to fix? Isnt that the point of renting? Yes, AT THE END OF THE TENANCY. During the tenancy loo seats are like light bulbs, the tenant's issue! You are confusing 'broken' with FWT. Landlords fix things that get broken. They don't put FWT right as an ongoing thing, during a tenancy. They get to put it right at their own cost once you have moved out!
You called them out for a plug... a sink plug? I am assuming it is one of those push/plunge plugs rather than a plug on chain! That would make more sense.
As for the floor, if they choose to leave it and you have emails then you will win that argument. If they do try to claim from you contact your nearest AIIC clerk and ask them to quote you the AIIC guidelines on wooden floors, kitchen worktops etc. At arbitration the landlord will be told that it was his to maintain!
Gas check - yes, you should have had more notice, but they can be last minute. Your phone interview, kids, lack of sleep and hormonal issues are not their problem, until you say no and ask them to rearrange. So you just say no, and ask them to rearrange!
Boilers can be contentious, most LLs will try to say it;s the Ts fault, because a lot if the time boiler issues are down to misuse, twiddling with the settings. Not all the time and, as yours went away when challenged, they aren't all that bad!
You need to get your head round the fact that whilst your LL has to maintain the place you also have to act in a tenant like manner. Which includes early notification of issues and upkeep of the 'consumables'.
A quick Google should help you with the loo seat replacement. If it is a tricksy one, and I have seen a lot that are, then yes, keep on at them. But chances are 15 minutes with a screwdriver will be all it takes.
Sorry that was a bit long. I'll take my Clerking head away now 