I wouldn't use "wild" crickets, I have found that they carry a lot of parasites, I have found all sorts of weird stuff swimming in my tanks after feeding circkets, google "horse hair worm" for an example. As far as the breeding in older fish, they certainly do slow down as they age, it takes an incredible amount of energy for them to spawn and raise fry.
I've also read about using a dither or "common enemy" to reinforce the bond between a pair of cichlids... not sure what is the exact reasoning behind that but the only time I tried it, it seemed to work. My Blue Acaras had been "flirting" for about a month but they just wouldn't spawn... then I added a small GT of around the same size and they went crazy... a little cruel but they ended up killing the GT and breeding the next day.
Thanks goodness, after reading about horsehair worms, it says they only affect insects and are completely harmless to all humans, livestocks, pets and plants. That's one less thing to worry about.
*Edit* to say I was really worried because I've been feeding backyard crickets, grasshoppers and beetles for years.