1. Do not worry, these are standard tactics of builder which are hardly acknowledged by court.
2. So in other words the builder will be liable for penalty put of delay and at the same time you will not be held accountable for penalty at such exorbitant rates.
3. The other charges does not appear to be legally tenable.
4. So get relief all these accounts you have to move to consumer forum wherein you can ask for penalty and compensation and damages for the acts of the builder.
Given the ill-repute of builders all over the country you would meet with success in no time.