Yes, I normally put the two ends of the address interpolation ways on the first & last buildings so these should be parallel to the footway. Ultimately we end up with all the buildings added, each with their own address, but it’s a good idea to go in manageable steps & address interpolation ways are excellent for this.

The sidewalks should also be tagged footway=sidewalk (that way a rendered map can ‘declutter’ by not showing the footways). Again, ultimately they may get chopped up into little pieces depending of how wide they are, what kind of surface they have, wheelchair friendliness etc. (This is another very good reason to avoid mixing tags for different things on the same OSM element: it saves a bundle of work if you decide to change something later.

Best,

Jerry aka SK53