I'm not sure about the SRD date but would you mind telling me what background do you have before I can answer your 3rd question?
As for 2nd question, you may check the status of your application from Shell website if you are applyin via the website. It is pretty update about whether you are being considered for the job or otherwise.

If you have applied the Internship through the website itself (www.shell.com), you may find out about the status of your application through the website itself by logging in with the username & password that you used while you filled up the application for this Internship. Then goto the "Application Status" and you will see the actual status of your application there.

If you have applied the Internship through other method (eg. career fair), you will have to wait for them to call you in order to find out about the actual status. I had a bad experience with them last time before(they forgot to contact me although I had been shortlisted for 2nd interview until I called them up). If you can't wait any longer, you may send them a friendly reminder through email or you may call them up to check the status.

Good luck

If you have sent them emails and receive no reply from them, I think you have to wait.
I extracted this FAQ from Shell website. If your status is still showing "shortlisted", I think it's still OK.

Q. How do I find out the status of my application?
A. As a first point of call, please check the 'Application status' page. To do this, log on to 'My Application' and click on 'Application Status'. Please see below an explanation of the statuses you will see throughout the application and hire process.
New Application - We have successfully received your application.
Application Under Review - Your application is currently being considered by a member of our team.
Application Incomplete - This status is only applicable for our Graduate & Early Careers candidates - if you are viewing this status after having submitted an application for an experienced vacancy, this unfortunately indicates that your application has been unsuccessful on this occasion.
Shortlisted - You have been selected to attend an interview.
Final Assessment - Following a successful interview, we are further considering your application.
Offer - Your application is being considered for an offer of employment.
Hired - You have successfully passed all offer conditions and are awaiting start date.
Reject - Unfortunately, your application has been unsuccessful on this occasion.