Wow, that is very well done Wade_G,
specially for a first build
The first thought I had considering you're using 24 gauge Kanthal was that it probably would take a while to heat up and the second was that the wire wouldn't get very hot. I ran it through the Steam Engine coil wrapping calculator and
got this with a 2.5mm I.D. at 20 wraps.
In the results window on the right, the heat capacity is 151 which confirmed the slow heat up time for me. I vape at around 40 watts and if I go over about 50 in HC I really notice the delay after I hit the button, specially when the coils are at room temperature. The higher your wattage the less heat up time there will be at a given HC, but even at 70 watts it's got to be noticeable.
The heat flux with your build at 70 watts is 97 which I find a bit cool, but this is totally personal preference. OTOH if you
change the watts to 40 it goes down to 55 which I think would not give you as good a vape as you could have.
The Kbox 70 will go down to 0.1 ohms. I'm running a dual coil build at 0.25 ohms at 40 watts using 24 gauge Kanthal. So the same wire gauge and I.D., but only 6 wraps (less wire mass to heat up). Here it is
in Steam Engine. Heat capacity is 47 and heat flux is 177. That gives me less than a second of coil heat up time when the coils are cold and I like the flavor of my juices at a HF of 177. I can turn that up to 70 watts and the HF goes up to 309 which will not burn juice so it's safe but it's getting warm. The HC stays at 47 and at 70 watts there would be almost no noticeable heat up time.
The resistance of your build has no effect on your battery amp draw in a variable wattage mod. That is controlled by the watts you set. With a VV or mech mod it's the opposite, the resistance influences the watts and the battery amp draw. As long as you don't get too close to your minimum mod resistance rating you're not pushing any safety boundaries.
Once again, kudos on a very nice build