call fidelity and ask them all these questions. This is all routine, very simple on your part and can be done in a day or two. The only thing that can hold you up is if your previous employer requires some sort of super secret password or pin to confirm your identity.
you can have your previous companies' stock in your rollover IRA. BUT, you will need a brokerage account as well. I've always found I cannot shed my employer's stock fast enough, so I have never done this. If you want ETF's, you'll have to get a brokerage account as well. Don't sell the stock, lay low and call Fidelity. They will sell and exchange for you.
Reasons not to rollover: 1) you think you will get sued sometime in the future and you'll have protections under EIRSA (or ERISA?) that your state won't offer for IRA's. This is a non-issue for me, since I never plan on being sued. Some people win lotteries, some people get pulled over all the time and some people never get sued. YMMV. 2) you make "too much" money and cannot contribute directly to a Roth IRA. If you rollover, then contribute to a non-deductible IRA and then try to convert to ROTH, you'll have to do it pro-rata. some people think this will be the last year Roth IRA conversions are around, I'm skeptical the gubimint will eliminate it since they have all these people doing conversions at 28% marginal tax rate when they'll more than likely retire in the 15 or 25% bracket. 3) you like the offerings your plan(s) offer (if it ain't broke, don't fix it).
It is quite simple to compare costs. I subscribe to the evil buy and hold, low cost investing approach. I simply head over to morningstar, plug in the ticker symbol and it gives a LOT of information. costs/fees are right there on the top line. top holdings (i think 25) etc. for bonds, it gives the avg duration, perhaps the convexity and the top holdings as well. I ignore the "stars" and who ever the fund manager is. For some reason, learning that Larry D Rufus is the fund manager and graduated from Wharton some 40 years ago gives a lot of people a secure feeling. I suggest you don't learn anything in the couple of sentences other than where the person went to school and how long they have worked for "the company." But, it makes great fodder at parties.
Picking funds is a whole 'nother animal. Educate yourself. You'll probably naturally have questions about asset allocation, and I suggest the Boglehead's wiki. http://www.bogleheads.org/wiki/Main_Page
Their book is also excellent, and every library I have ever come across has it.