How are qualia localized in consciousness?
This question has been unanswered for a long time and I will attempt to address the issues posed not one by one, as there are a great many questions, but with an overall working of the sensory nervous system with respect to topographic mapping. Moreover, the question uses a great many "suppose ifs" that have never, and most likely will never or cannot be tested. Therefore a basic overview of topographical mapping may shed light on the matter.

The somatosensory cortex is a highly topographically organized structure. Although warped in size, it basically contains an exact topographical map of the body, referred to as a homunculus:


Source: Guardian

In other words, perceptions in the upper arm are represented very near to the lower arm representation in the somatosensory cortex. The motor cortex contains a very similar map.

Similarly, the visual cortices contain many maps representing the visual field, referred to as the retinotopic map. Likewise, the auditory system maps frequency space in a highly topographical manner (the tonotopic map).

Removing a part of the somatosensory cortex out of its context may wreck havoc on this ordered structure. For example, it has been shown by groundbreaking work from Michael Merzenich and colleagues that when the fingers of a monkey are sewn together, the finger representations in the sensory cortex also fuse, i.e., the border between the coupled fingers degrades and vanishes eventually. This experiment shows that when two separate bodily structures are repeatedly and structurally stimulated simultaneously, they fuse in the cortex. Upon separation, original mapping is restored (Allard et al., 1991). I consider this proof that adjacent structures influence each other's representations in the cortex because they often receive parallel stimulation. Coherent stimuli typically result in increased synaptic strength. 

Phantom limbs are interesting indeed. For example, the groundbreaking work by Ramachandran focused on upper arm amputees. These folks would feel sensations in their (amputated) hand when their cheek was stimulated. In the homunculus it can be readily seen that facial representations are close to the hand representation. Upon deafferentation of the arm region in the cortex, surrounding bodily representations take over the 'silenced' regions, and the cheek region 'steals' the hand (which is relatively huge). However, interestingly, the cheek not only serves its own original representation, but refers now to the amputated hand as well. Hence, the memory of the hand lingers, showing once again that the bodily map is strongly imprinted in the brain and that it is not simply isolated from its context.    

How then are visual and tactile stimuli fused as being correlated? This happens in the higher multi-sensory areas in the brain, the so-called association cortices such as found in the temporal lobe.


Source: Insituto Balseiro 

These higher areas will link various perceptions and merge them into coherent perceptions. Limbic association areas may couple the butterflies to love. 

Conclusion
In all, qualia are localized in the brain by mapping sensory information onto highly organized topographic maps in the cortex. Changes in the periphery (e.g. amputations) will affect this cortical mapping due to plasticity and hence these cortical maps are plastic (subject to change). The reverse can never be easily tested (taking a piece of brain away will have gross consequences) as said, but I think that the quote "Neurons that wire together fire together" is important here. As said, synaptic strength increases when adjacent neurons fire in coherency and when taken apart their mapping will become distorted. Lastly, emotional feelings are combined with the physical sensation of butterflies in your stomach and synthesized into a holistic feeling of love, probably by the limbic association cortices and perhaps other association areas. in general, the association areas synthesize the various sensory systems by linking them, most likely due to experience.   

Reference
Allard et al., J Neurophysiol 1991;66:1048-58