Hi Mitch, welcome to the forum
. So I have read your writings and the comments that followed, and here's my weigh in.
You were told that you and your fiance are both sensitive to paranormal activity. After a few of my postings on here, some of the members feel that I may be sensitive as well, and Debi referred to it as being a beacon. I did do a little research into it and in a case like that, a person who is a beacon is like a magnet for paranormal activity. So that being said, it may not be the house or the property, it could just be those that are sensitive to paranormal activity. I think read some of my stories and see if any of the comments there give you some extra information that may provide some clarity on your situation.
So you said you split the house with your parents, and the house has been around since the 60s. Now I'm assuming that the renovations that took place to achieve this were not minor. From what I've seen, the older the premises, the more likely paranormal activity can occur when renovations take place. So that may be a possibility to look into. In some cases even a slight change can trigger a massive haunting, like with me in 2010 (see
Haunting of 2010/2011).
In terms of the animals, as Debi mentioned, they are much more susceptible to paranormal activity. During my 2010/2011 haunting I talk about how my dogs reacted strangely during a stage of severe activity. But you don't necessarily need to be concerned when your pets stare at something you cannot see. If an entity is dangerous or malevolent, pets will normally show more signs of fear. In some cases, they will become restless and try to get out and away from whatever it is that they are seeing or sensing, or some dogs may bark aggressively at the entity.
With regards to your heart-lung condition, there can be rare cases where it may be paranormal related but this can be extremely difficult to confirm. As Paintman mentioned, mold or mildew can cause problems with lungs, but mold can also cause other problems which could be a possible reason for seeing movement in the corner of your eyes. I'm not saying that it's not something paranormal, but try rule out the mold theory if it is true.
You said that the humidity in your side of the house differs abnormally to the humidity in your parents' side. I'm no expert on the subject but just thinking is it not possible that there is something wrong with the ventilation or maybe it was not installed properly? It's just a possible theory that came to mind when I read your description of the matter. Maybe see if that isn't the cause?
You mentioned sensations of dizziness and feeling weak, and you also mentioned you smelled paint. Now I saw in the comments Debi said it is possible for the odor to be released from the wood. I'm just thinking if it maybe isn't possible that the chemicals in the odors are not causing this? I don't know if such a scenario would release a strong enough concentration to cause dizziness, but it's also a suggestion that maybe one of the other members can confirm.
With the matter of your fiance sleeping and waking up feeling tired. This happens to me often when I go for an afternoon nap. My room is not properly ventilated so I would lie down, sleep very well and wake up feeling twice as tired than I was before I laid down. This is another reason why I'm thinking it could be something wrong with the ventilation system on your side of the house as well.
Now the audio recordings you uploaded. The Creepy.mp3 sounds like a bird. Did you amplify the sound before uploading here? I'm from South Africa and I have a wide variety of birds that stay on my premises, and some of them can get extremely loud. But it could also be an insect, there is one insect, the cicada, that can produce a sound as loud as 108 decibels, so don't rule that possibility out yet. The pop in the house actually sounds like something falling off from somewhere, or something knocking against wood. Was anything out of place in the source of the sound? Could the dog maybe have heard something else that we can't hear and jumped off from somewhere making that sound just before he started barking? The whistle mp3 I don't know. Listening to that one actually gives me chills, and that I think you may have captured something paranormal. It sounded too human to be a bird or insect.
I'm not trying to sound like a skeptic, I'm just putting myself in your situation and trying to see what's the first thing I would look for in situations like that. I just suggested possible alternative causes for these occurrences so that if that's the cause, then hopefully it will help put your minds at ease. I'm not doubting that there might be something paranormal in your house, and I'm very interested to hear more updates and review more recordings and give my input wherever I can (and as you've seen so are the other members). But I wouldn't feel threatened by whatever is in your house yet. The case with your lung could have been a nasty coincidence, as I said, linking medical emergencies to paranormal causes is very tricky. But from what you have described it doesn't seem to indicate anything malevolent, but I'm sure through more updates we can try determine the true nature of the situation.