I am curious the current state of affairs going by bus from Kunming to Dali. How long has it taken for people who did it recently?

The problem with busses to Dali is that there are some really crazy drivers who do the trip of 340 Km (Dali old Town) to Kunming West bus station) in less than 4 hours. That includes a stop at the very filthy Shaqiao bus stop. You don't have to understand that these busses drive well above the safe speed for which they are designed. Unless you know which busses are safe I would not take them.
I recommend everybody to take the train which is more interesting and safer and even much cheaper. (The city bus from Xiaguan to Dali Old town is 1 RMB. Train last time I took it 64 RMB)

Take the big bus (45 passengers) to Xia Guan (Dali) rather than the smaller buses. 4.5 hours is the usual time although some are a bit faster and some slower.

How about taking a train from Kunming to Dali? Is that difficult for backpacker？

Easy to take either train or bus. I wouldn't worry about safe/unsafe busses. The train is less polluting - if you take a day train (I think there is still one, but I might be wrong) you'll actually see something of the country and people. When you get to the Xiaguan train station take a local bus to Dali Old Town, about half an hour away.

Is that difficult for a backpacker? What does that statement mean? Was it difficult to take a bus? Aside from time, bus/train - 4/8 hours, there is no difficulty.

What IS a 'backpacker' these days anyway? Do you get put in another category just because you get on & off an airplane with a backpack instead of a suitcase?

www.urbandictionary.com/define.php?term=backpacker

Backpackers are a very loose subculture of travelers who carry all their stuff with them in a backpack. Typically they are driven by a sense of adventure, and as such are always trying to find somewhere beautiful, completely off the beaten track. They often travel as cheaply as they can to maximise the time they can spend on the road, accepting squalid accommodation or sharing rooms if it will save them any money. Most are in their twenties or early thirties, and almost all are between 18 and 40 though older and younger people aren't unheard-of. People go backpacking for all sorts of reasons but will almost always take offense if it is implied that they are 'on holiday'; backpackers typically consider travel a separate, more serious engagement, all about broadening the mind, experiencing other cultures and trying to satisfy what is often a deep-seated and more often than not insatiable wanderlust.

Can these goals be reached on a point-to-point basis with the connecting links being airline flights?

No. 8 bus goes from the train station to Dali Old Town, the West Gate. The main Xia Guan bus station is a few blocks from the train station, perhaps a long walk. A 3-wheeler will take you there if you don't care to walk. Taxi from Xia Guan to Old Dali is pretty expensive.