1. For your query No.1, Service Tax can be charged by the society if your maintenance charges exceed Rs.5000/- every month. But it will not be charged on Govt/ Statutory Charges, Security Charges if it is exactly covered by the Society and paid to the contractor, Insurance charges etc. So for a more clearer view we would need the exact break up of your bill and also if it is cost to cost or the society is keeping a markup.
2. Service Tax can be charged by the society if they are charging you a convinience fee of some sort on the electricity bill, then only upto the limit of the fee. If that is not the case then I assume No Service Tax can be levied.