NPK 12-10-16 too hot for seedlings?

It's all about what you dilute it down to. A NPK of 12-10-16 is a fine ratio for veg, but its the concentration of the solution in PPM/EC is what will determine if it burns. eg. a EC of 2.0/1000ppm of 12-10-16 would kill it, but a ec of .2/100PPM of 12-10-16 would be fine. Soil does not normally need feeding till about week 2 or 4 depending on how its fortified and if its really soil and not soilless with slow release fertilizer beads, but coir and other hydroponic systems like DWC/rockwoll normally do need feeding from day 1 as the medium is void of nutrients. The seed has enough energy to pop a tap root and sprout above the surface, other then that it will need something else if you want it to grow strong. again soil normally has this and hydroponic systems tend not to. Good Luck!

Thanks @whiteybulger but all I want to know is if the seedlings can handle this soil.

You don't need any food for seedling...