Just remember that good quality tapware is EXPENSIVE and so is the plumber to change out the tap so go for the best you can afford - tapware will either make or break the look you're going for in terms of big ticket items. But go for what you want - infact take a sample of your benchtop and put it next to the tap and a stainless steel appliance in the Ikea showroom and have a look to decide for yourself - it all depends on personal taste.

sounds like you need to talk to a Plumber who specialises in commercial hotel installations but a quick Google also revealed a product called a "Kegerator" and wonder if that could be useful for your dilemma??

Did you Google and do any research on the WELS certification? https://www.waterrating.gov.au/check-product-rating. It’s just an efficiency ratings so you could risk using a product that doesn’t have the rating. However a quality plumber may not install it. AFAIK all taps on Australia require a WELS certificate. But the gov website does have a database. And yes lots of the Billi taps have the required WELS rating.

Could be. But given the fix for a mounting problem is opening up the walls I’d be trying the DIY water hammer method first. You could also try seeing if it occurs if you tip a bucket of water slowly down the drain.