Damascus is 99% for appearance. There could be a minor argument made for the cladding increasing toughness in the same way san-mai does. Also, stainless steel included in the damascus will add to the corrosion resistance of the end product. However 1080/1095/15n20 are all non-stainless and won't resist rusting or patina, nor will any particular one add much toughness to the blade.
Day to day maintenance for these steels (pattern-welded together) is the same as any carbon steel knife - so no it won't be harder to maintain and yes, it will reactive.
The biggest problem will occur when you try to thin the knife, relieve the shoulders, raise the shinogi line/primary bevel - basically anything that scratches up the sides of the blade. This kind of longer term maintenance will scratch off and remove some of the pretty patterns. It's possible for you to bring them back with things like ferric-chloride etchant, sandpaper, etc... The level of difficulty to do this is medium to high, depending on whatever Mert did to finish it and how fussy you are with how it looks.
