Danielle,
Depending on the size of your bluey, the tiny crickets may not bother it - but I would definately place a carrot or slice of apple in there for the insects to eat. This will keep them away from your bluey's toes at night. As they grow, maybe you can catch them and remove them.
I hope you are providing more than just crickets as the primary food source. Crickets are often the poorest form of nutrition unless gutloaded. Blueys need a better diet than just crickets. Depending on age, they should be given a good amount of protein along with greens and fruits.
We don't use moss in the regular part of our bluey enclosures, as they might ingest some with a meal, and possibly cause a blockage. If you want to provide a moist hide for ease of shedding, put the dampened moss in a plastic shoebox with a hole cut in the side - the bluey can climb in there when he/she wants.
Most bluey owners use care-fresh/aspen chips/bark for a substrate. Many decorate the enclosures with cork rolls and logs and even silk plants. They provide an area for basking (a piece of slate or tile), on the warmer side of the tank.
Most bluey keepers spot clean as needed and change out the substrate after a shed. Once per 4-6 weeks is a good average for general cleaning.
Hope this helps some,
