HELP: The Future of the S&T Job Market and Selecting the Right Desk

Hello WSO. I just accepted an internship offer at a top bulge bracket bank for S&T this week. My only issue right now is that the internship is NOT rotational so I have to make sure I'm on the best desk for me this summer. I know this is mainly an IB forum so I've been having a hard time finding forums on here that give insight on the sales and trading industry. I'm open to hearing ANY advice or thoughts anyone might have. If you disagree with anything I say please voice you thoughts! :) thanks.

There are three things I would like to figure out right now:

1) Determine which desk (equity, credit, rates, derivatives, fx etc.) would be best to start a career in S&T in general and what areas are expected to shrink or expand due to regulations - market forces - technology.

-Right now my thoughts are that equities have been doing well recently. There's been a lot of M&A activity and since the crisis the stock market has boomed. The only caveat of something like a cash equities role is that the work has been phased out by technology.

Personally I view it as a purely relationship driven role where as a young analyst I will develop limited fundamental knowledge/experience. I'd rather have my career rely on my fundamental / technical knowledge than my ability to become best bros with my clients.

-Fixed income has seen a recent headcount cuts because of weaker bond trading. What do people do once they get fired? Banks are seeing bond-trading revenue decline by up to 40%!

Right now I'm interesting in credit sales but I'm worried about the space shrinking. Should I avoid sitting on a credit desk because the market is shrinking or should I not be worried given that I'm young during this downturn?

2) Which position sales vs trading presents long-term earnings potential and other career opportunities. I want to know that if I'm faced with job cuts because of the market (no wrong doing on my part) that other firms/banks would be interested in hiring me because of my experience as a salesperson/trader in my particular product.

-I'm discouraged from doing anything in trading at BB because from at least what I've read on WSO it's mostly a market making role and should be avoided if you're looking for career longevity.

3) What questions would you ask yourself to determine what desk is best for you? What are important considerations for each desk and sales vs. trading role?

-I do my best to network but I sometimes I just don't know what to ask! If you got an opportunity to speak to people in sales or trading on various desks what would you ask to determine if it was right for you? I wish there was a PDF with all the different desks at a bank and the kind of work you'll be doing and the kind of person who excels in that role. I feel for IB analyst there are exhaustive resources for this that exist online but for S&T information is extremely limited.

Please let me know your thoughts. I'd like to have a solid discussion on these topics. I know that a career on Wall Street doesn't provide perfect job security but I do want to make sure that what I choose to do won't be useless in five years. And thanks in advance - I wouldn't have this opportunity or be able to handle my interviews in the first place without WSO!