Dear sir
1. Yes DSP will consider past records as you have given complaint to police in written.
2. Yes DSP or any police officer they all know that in 70% of cases SC ST act is falsely used against other party to escape such liability
3. They have to consider as it is a matter of record as you say you have the compromise in written but you should have these documents with you.
4. In current scenario i should say that you have to be more careful as you talk to your neighbor install CCTV cameras which your neighbour don't know with voice recording in your premises. Also whenever you talk to him or his family member record the conversation and keep it for a while to be safe.
5. Your neighbour will keep on using this as weapon against yours future until you cut dont take any action.
As soon as you come out of this situation clean handed file a complaint against him and his family member in court under section 389 of Indian Penal code with all the documents and photographs available with you for your defence this section is
Putting person in fear of accusation of offence, in order to commit extortion
Extortion can be of any kind as in this case extortion is he make you to do some work you don't want to do