I agree with radiantman. I prefer central done right whenever possible. It seems like you'll have the opportunity to it right with the walls opened up. The key thing is to get it done right. A properly-designed and installed central air conditioning system will provide years of comfort. Once you "cover everything back up," you won't have units hanging from your walls. Ductwork design is extremely important to have a good central air system.

I couldn't get to open but prob bc of my phone. The single head units are a lot more efficient then the muti head units. Not sure from your setup but you could possibly also use fans to help push the air through the house.

I do not anticipate any problem with either location in the BR. I would not want one right over the bed since as they approach set point the blower slows and cold air will fall on the bed like a waterfall. After switching to seven mini splits from a ducted system, I have not missed a cold air duct in the bathrooms. Mitsubishi has a feature called "iSee" available for some of their high wall units. They have an infrared sensor that is used to point the air flow at the warmest area in the room. I can't say how well it works. I suspect it might drive my wife nuts since she does not like AC blowing directly on her. Since a person would likely be the warmest part of the room, it seems likely that it would follow a person around.

Ductless is not going to offer “air purification” or lower noise. With ductless, you have a blower in each “head.” The air filtration is just the basic dust-filter like is on a portable AC. As others have said, 1600ft ranch is too small for 5 zones. Probably you’re looking at bedrooms on one zone and living areas on the other. But you shouldn’t really think of it like that - orientation matters most. Consider the heat gain at various times of day. If one bedroom is on the East side and one on the north side, the East bedroom is getting cooked while the north bedroom is experiencing little heat gain. Mini-split doesn’t necessarily mean ductless. They can be hooked up to small or full-size air handlers. You could do two separate mini-split ducted systems - one for the bedrooms and one for the living areas for example. This will likely give you the best efficiency and comfort. Mini-splits don’t modulate nearly as well when multiple heads are connected to one compressor.