One suggested using spray foam on the underside of the attic walls (roof) and the other suggested blowing in cellulose over the floorboards of the attic.

N1102.2.8 (R402.2.8) Floors Floor framing-cavity insulation shall be installed to maintain permanent contact with the underside of the subfloor decking.

The helps to equalize the temperature between the top and underside of the roof.

The way to do deal with the condensation on the underside of the metal roof, is to install it on a batten/counter batten system and provide an air intake at the eave and air exhaust at the ridge.Galvalume is great type of metal roof for sure, just be careful about the condensation issue.