Oh yeah, use the TDEG given under EFFY as your goal eating level, no need to do the math yourself.

The strength training depends, as ryry mentioned, at the start it could very much be a heavy lifting routine for you.
Meaning you can manage about 3-5 sets of 10-15 reps, or less, with good form, and then too difficult beyond that.
If at that level to start with, and you take 1minute minimum rests between the sets to recover, than count as lifting.

When it gets easy enough you are doing 15-20 reps without an issue for great majority of exercises and rest is minimal because you don't need it, you can either add weights, or start counting it as probably high cardio if it feels that intense.

As to why the BF calc's show such variance - merely different body types.
People gain and lose their fat in different spots.
And some people have body shapes that will always have some part out of norm compared to the others.
You look at those measurements, you can probably tell which measurement is out of whack right now.
Could be a small wrist paired with normal sized forearms. Could be big calf paired with smallish thigh or hips.
And it may have nothing to do with fat, may just be body shape could never allow for good estimate on those calcs.
Those 2 are usually considered the best, testing well for vast majority, forget the stats right now in couple studies that included them.