I can answer 2 of your ?'s.
First one, you will find that the bigger the aircraft gets the less you look out, I mean especially flying IFR, (NOT IMC) IFR, when on an IFR flight plan you have to maintain your altitude and course very strictly, so just flying around joyriding and looking out goes out the door, your scan has to be so regular to maintain those requirments that little time is left to look out. That is if you are hand flying. I found when flying Transport aircraft, I rarley look out except for the occasional looking at the stars or sunset. Also, everything is an approach in transport aircraft, not required, but if there was an ILS on the runway I was landing, no matter if it was clear and a million, for saftey reasons and just making it easier to stay on a good GP, I would fly the ILS. If no ILS and it was VFR, always flying the VASI or PAPI or what not. THe larger the airplane, the harder it is to tell your distance from the ground, so vertical course guidence is a BIG help, not including a BIG saftey concern.
Other question, how long to feel comfortable, that really depends, I think, on your average experience level. I mean if you have only 500hrs then it will take you some time to feel comfortable, but after flying a few larger turbine aircraft like the B100, B200, SA227, you get to be able to feel comfortable pretty quick transitioning to something of equal size. I mean if you go from flying a B200 to flying a SF340, then you won't have that big of a comfort problem, I don't think, but going from a C172 to a CRJ, well that is self explanitory. That is why I still can't understand why they let guys with 350 or 400hrs sit right seat in a CRJ with 50 people in the back. The practical experience level is just not there. Everything is fine as long as the guy in the left seat is ok, but if he is out of commision, you are going to wind up with a serious problem I believe, especially if multiple things are going wrong.
AS far as power settings, not sure, I have flown the 200, the 90, and the 350, but never the 100 so I couldn't tell ya.
Just play around on the ILS and trim it well and see what power setting gives you the right decent rate for the GS and there ya go. Shouldn't take you long to figure them out. Take care.
SD