I'm new to this as well but I'll answer your questions as well as I can. Beautifuldragons.com has a nutritional list of food items for bd's that is widely used by this site. It can be found here: http://www.beautifuldragons.503xtreme.com/Nutrition.html
The list has blueberries as black for "Feed occasionally" and Raspberries as blue for "Feed rarely". So for that reason I would say that yes blueberries are good for them and they are also better than raspberries.
As far as crickets go. Crickets are not the best source of nutrition for a beardie but some people (myself included) use them as staples based on necessity (My bd is too small for supers and I can't use/afford other staples). Just be sure to dust them in calcium powder ever 2-3 meals and they will be fine though. To make sure your crickets live long keep them dry and make sure they have food and water. You can buy a crystal that you mix with water to solidify it to prevent drowning as well as reduce smell. I use cricket feed together with this to eliminate food odor from my cricket tank. Also make sure you have something for crickets to hide in and get off of the bottom of the cage such as egg cartons so they are not living in their own feces. Also make sure your crickets are neither too warm or cold, I personally keep mine in a cupboard under a bathroom sink separated from any kind of cleaners or other such chemicals. These things together with regular tank cleaning keep odor down and conditions healthy. Follow these steps and you should see a lot less die off in your crickets which saves you money.
I don't know much about supers as I haven't used them yet since my bd isn't big enough yet. What you read about them being bad might have been the fact that you are not supposed to feed them to a bd under 18 inches in length. Until this length or thereabouts bd's have a kink in their digestive tracts which makes these pose a risk of impaction. If your bd is close to this length you can try feeding it a few and then check your lizard's feces to see if there are any large undigested parts of the worm in it. If not then you are good to go. From what I understand supers are fine as a nutritional source for your dragon and need to be dusted every 2-3 meals the same as crickets.
Also avoid meal worms as you've heard before because their shell is hard for your lizard to digest properly. If you cannot use dubia like me I would normally recommend silk worms or phoenix worms. Unfortunately their has been word that the silkworm population has been getting sick from some kind of disease recently so I would avoid those, and phoenix worms are very expensive. So for you I'd recommend crickets until the bd is over 18in then swap to supers and supplement with some of those blueberries and more and more leafy greens as it gets older (18months being the point where they tend to predominately eat greens).