Katanas can be finessed by medium characters (much like Rapiers), it is a HG specialty. Dual wielding katanas is possible, but problematic (although it can "feel" edgy). 1. Only one of your equipped weapons can be honed and deliver MS. 2. You will end up with -4 AB on both weapons; the build you linked ends up with around 90 AB at lvl 60. That is borderline low in hells and it doesn't get much better as you progress further. 3. You will need to collect (and craft) twice as many weapons as normal. Among other drawbacks, casters will hate you, if not outright refuse to buff you.
Yeah, looks like u can cs anythin non crit imm. - Big Crit