How is it possible to show live updates of job status in a custom tool made in house which submits jobs to deadline ?
That depends on the API you’re using, check out the scripting overview to get your bearings.
If you’re unable to put the Monitor on artist machine you’ll likely be using the RESTful API. To pick out the two verbs you’ve mentioned, you can get the status of a given job with GetJob and submit jobs with SubmitJob.