1) Is it possible to start R sessions on Linux (e.g. Rsession1) and submit multiple jobs in batch mode to the same R Session (e.g. job1 to Rsession1 and then later on based on user action submit job2 to Rsession1)?
This is equivalent to opening interactive R Session and submitting job1 and the user can submit job2 in same session (which will be available until the user closes interactive R session)
2) Is it possible to start two R sessions on Linux (e.g. Rsession1 and Rsession2) and submit multiple jobs in batch mode but specify session-id during job submission?
This is equivalent to opening two interactive R Sessions and submitting jobs to different R sessions by clicking on the window manually submitting the job.