Hi Dusty Hydronic towel rails can be a great alternative to traditional panels in a bathroom. There is a huge range of design and budget options on the market. The main difference between a traditional panel and a hydronic towel rail is the way it projects the heat into the room. A traditional panel is mostly convection (around 20% radiant heat) so the heat is released through the top of the panel up to the ceiling then forced back down the heat the room. A hydronic towel rail will be purely radiant as it doesn't have the vents on top. With regards to to heating up the room is always best to oversized with a towel rail mainly because depending what finish you go with the coatings may affect the heat output and also as soon as you start putting towels on them your blocking the heat, you will end up with nice warm dry towels but not necessarily a warm bathroom. I hope you found this useful :)

You can do timber and wire internally for your balustrade in the mezzanine. You need to keep with the aesthetic of the home. And do the outside deck balustrade as well.

I’d be checking that the aluminium battens are scratch and dint resistant, is so they do give more privacy than wire and are less climbable. I had stainless steel wire, that was meant to be marine grade and it still discoloured, in a house close to the coast. The humidity in your area may cause the same.

Agree it comes down to preference. I would consider how much of the board and batten you would actually see once the bed and other furniture is in the room. I love the B&B look but if you aren’t going to see the impact of it, why spend the money?