The hardest part of this whole game is being unwilling to do the work to find out the answers. You're here at FT. Staying on top of information means regularly reading FT because the information is here. You will have to do some work to find it. Fortunately, not that much work.
For instance, near the top of this forum, an entire thread devoted to your first question:
http://www.flyertalk.com/forum/miles...er-thread.html. You can find the best current deals in this thread. The best current deal for you? It'll depend on a lot of factors, such as the airlines most available/useful to you as well as redemption on their partners, what your ultimate travel goals are, and how good your credit is.
When you talk about transferability, I'm assuming you mean for the two major credit card points rewards programs, Amex's Membership Rewards and Chase's Ultimate Rewards. There are forums here, under
http://www.flyertalk.com/forum/credi...-partners-390/, with threads on those topics.
Which cards are more valuable than others? That's kind of like asking what's more valuable--a painting by Van Gogh or a painting by Renoir? If I despise Van Gogh or Renoir's work, there might be no value at all to me. In fact, I might find more value in the paintings of dogs playing poker. As you do more research and refine your travel goals, you'll start sorting out for yourself which programs offer you value.
You can get advice from sources other than FT, some of it more easily digested than here. A number of bloggers do that well, including the Frugal Travel Guy, The Points Guy, and Million Mile Secrets. Keep in mind, however, that the more easily digested the information, the less specific it will be for your specific travel goals. Plus, each blogger has his own travel goals, and his information, whether he acknowledges it or not, is colored by that.
There are forums here that also talk about travel destinations all over the world as well as trip reports, including information on flights, hotels, and sights seen once on the ground. It's a good idea to look at those forums. You might find that your original travel goals may change once you've seen more options. There are also individual airline and hotel forums with a number of experts at each who know how to stretch the miles and points you've earned.
You've asked a lot of questions. The truth is there are even more right, although few easy answers than there are questions. Figure that travel and mile/point accumulation has just become your new hobby. To get good at that hobby, you'll have to spend some time doing the necessary reading and research.