WagonR Lxi Duo 40000 kms servicing queries

I took my WagonR (Lxi Duo ~42000 kms) for servicing today at Motorcraft, Noida. When the SA told me that its going to cost me approximately Rs 7000/-, discounting wheel balancing and alignment (as I had recently added new tubeless Michelin tyres), I was shocked! He told me that all the oils (engine, gear, brake) would be replaced. Apart from that the injectors, spark plugs would also be replaced as part of 40000 kms service routine and quoted Rs 550 and Rs 300 as labor charges for them over on top of the service labour charge of Rs 950/-. Total labour charges were coming to around Rs 2200/-. So I decided to take my car back and check out TeamBHP forums regarding this. 1> Do you guys think its a usual amount for this service as I have seen Rs 5300/- as the charges for a 40k servicing in 2009 on this forum with the wheel alignment? 2> It seems that the LPG gas is leaking under the bonnet evident from the smell when the bonnet is opened / after every fill up. The SA told me that he had to replace a part which costs Rs 2500/-. When I asked him if the part is under warranty (as my car is under warranty), he said that since its a rubber part, it isn't covered by warranty. Is he speaking the truth with respect to the part's price and it not being covered under the warranty? I am sorry but I don't know the part name but it is right next to the LPG gas filter. 3> Creaking noise comes from the suspensions when the car goes over those plastic bumps/speed breakers in Noida. Can I get them repaired or do I have to get them replaced ? 4> The engine oil was replaced around 7000 kms ago. It was Castrol 3.7 ltrs. Do I need to change it again now or should I wait for 3000 more kms before changing it ? 5> Do suggest which is the best gear oil, brake oil and engine oil for a WagonR like mine.

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