Hmmm, yeah, lower approach angle, less wheel clearance before the runway - more chance to hit something that could really spoil your day. There is a potential for tailstrike on landing, in longer bodied aircraft too. I've made much the same points on the thread that Slash started.
I tend to agree with CPB about being slightly low on a PAPI or VASIS but it's a "horses for courses" issue. I certainly don't have a problem with that in the Kingair. But, as Slash has said, a deliberate deviation well into the reds is a real worry, IMHO.
As for "the step"... I've been flying Kingairs since 1986 and have never seen the necessity to bust the cruise altitude to dive back down to it. I find that the aeroplane only needs a couple of minutes to accelerate after levelling off from the climb. Then set cruise RPM (1700 RPM) and sit there fat, dumb and happy.
Why complicate something that doesn't need complicating?
I guess there's one further point that I should make here about PAPI/VASIS approach angles. Part of my job entails periodic flight checks of the various approach path angles.
It can be very difficult to maintain any particular approach angle in turbulent flying conditions. One of the checks involves a deep penetration into the reds, to check terrain clearance and I can assure you that, once you're seeing 3-4 reds on a PAPI, or mostly red on a VASIS, you have no real idea of the actual angle of the approach. You are also vulnerable to further excursion downward due to turbulence.
I've been doing the same job for 16 years so I've got a few ideas on how to do it safely. But, all things considered, this is not the sort of thing that a professional airline pilot should be attempting, even in a flexible aeroplane like a Dash-8.