You can assume that if you want seeds to germinate, the soil needs to be kept moist. Not sopping wet. Just moist. Once they germinate, and send roots southward, surface moisture is irrelevant.
Soil temperature requirements really depends on the seeds. Winter crops are happy to come up in cool soil. Summer crops (peppers, basil) want warm soil.
Depth? Just follow the instructions on the seed packet. But yes, the soil needs to be loose and friable. If the soil turns into concrete, nothing will come up. Mulch over concrete won't help.
As to direct seeding, if cutworms are an issue, you'd be better off doing transplants. Why? Because then you know where the plants are, and can protect them. If you direct seed, the seeds will move around, and the cutworms can get to them before you have a chance to protect them. In general big seeds (squash, cukes) make big strong seedlings when they germinate. Small seeds (peppers, tomatoes) make small delicate seedlings when they germinate. So direct seeding the latter can be chancy.
