Team-BHP - Service query

I own a Swift that has completed 25k kms. Vehicle has been serviced at 1000 kms, 5000 kms, 10000 kms, 20160 kms (Not authorized Maruti dealer).

Though manufacturer recommendation is to service every 10,000 kms, Iam thinking of getting it serviced every 5k kms. Service cost would be in the range of Rs.2000/- (40 paise per km). Iam under the impression this would help the engine to be in healthy condition.

Just wanted to find out, whether this service at every 5k KMS will really help in keeping the car in good condition or it's a sheer waste of money?

Also Iam planning to switch over to Mobil Sythentic oil. Which grade is recommeded for Swift? I had instructed the workshop to flush the compartment before they switch to Sythentic, if they failed to do the same, will it result in any complication.