1. You are the member of the society and not separated from the Society,
2. All such decisions are taken by the society after passing resolution in AGMs or Meeting of Board of Directors selected/elected by you,
3. For changing the Decisions of the society, you should call for discussions in your next AGM to alter them if majority of the members agree,
4. As regard your specific questions, the decision of charging Rs.250/- towards owner night parking of the guests cars is well within the rights of the society since the guests are using the car parking space for the night and if such charges are not made any guest(may be from nearby society having no car parking space but a fiend in your complex/society) can park his car for every night which no body can object to legally,
5. Charging of penal interest for delay in paying maintenance is followed by all the societies otherwise there will be no payment compulsorily made for running the Society duly providing maintenance services, paying salary to the employees etc.,
6. If you do not know whether the bye laws of the society has been submitted and recorded before the Registrar or not then find it out from the Registrar. Visit the registrar's office to investigate on the matter. You can also take the RTI route to get the said information,
7. Finally, it appears that you are treating your society as 'they' whereas it should be treated as 'We' and you are also liable and responsible for any action taken by your society unless you put on record your objection against any of the decisions taken by the Society.