Putting aside pickup tilt for a moment, D/G volume would be affected by what the gauges are *relative* to E/A gauges. Increasing all gauges would increase the volume of all strings so the problem would remain. But anyway, indeed, tilt your pickups to balance volume.
45-100 is not 'light or extra light gauge', it is fairly medium.
Yes, tension depends on string mass which is mostly determined by gauge.
Not so, this is a misunderstanding. Tension is determined by scale length, pitch and string mass (see the D'Addario and GHS tension documents to confirm). So tension is certainly affected by wrap wire.
So this is not possible.
It seems the confusion here is that you are using the word 'tension' but are referring to 'stiffness' which is a different thing and independent.
The confusion between 'tension', 'stiffness' and 'how it feels' (which are all different things) is extremely common on this forum, so you have probably been misled.