Dear Sir,
1) Yes two relatives or friends can buy Agricultural lad together.
2) Now any Indian, or a trust, society, company or an educational institution can buy farmland in Karnataka regardless of the buyer's annual income from non-agricultural sources. Thus being from agri family is not a need, regardless of it you can buy agri land.
3) In Karnataka, the Karnataka Land Revenue Act 1966 has prescribed the procedure to convert agricultural land to non-agricultural, under Section 95 of the Act.
The purpose for the change in use of land must be specified. The Deputy Commissioner may grant permission and may even impose conditions. The law prescribes a penalty in case of violation of the procedures.
4) Conversion involves seeking the approval from the competent revenue authority which is the Collector, Sub-divisional Officer (SDO) or Tehsildar. The process can also be undertaken online through govt site.
Thank you