a) As far as I know SK never had a firm order on the MD-95/B717-200. The B737-600 was ordered before ValuJet launched the MD-95 wiht an order for 50+50 frames.
b) LHMark: Ehm, which are the destinations you are talking about? FMO and PAD could possibly support a 100-seater but I´ve my doubts. AGB´s runway is way to short and LH has just confirmed that they are cancelling all IQ operations out of AGB, leaving 2 Dash 8 idle. And GWT with a 100-seater is joke, the largest equipment operating into this airport is a ATR 42 as far as I know. LH Mailine will in future concentrate on domestic services which can support B737/A32X, everything smaller will be given to either CL, EW or Team Lufthansa.
c) Lufthansa will mostly likely always have a mixed Boeing/Airbus fleet, LHs B747 fleet is around 30 frames strong plus about 60 B737. The A32X fleet is around 80 frames strong, the A300/310 about 20 and the A330/340 fleet about 40. And as Airbus does not really offer a suitable B747-400 replacement those birds are going to stay for a long long time.
d) The B717 is and will be a stand-alone if Boeing doesn´t go ahead with a new version. And as a stand-alone it does not make any sense for Lufthansa due to scheduling and crewing issues, they are much more flexible with a CRJ (EMB?)/A32X (B737) Mix than a CRJ/B717/A32X/B737 mix. And don´t forget the scope clause issues at the carrier. Mind if I throw another option into the game: additional CRJ700, new CRJ900, new A318, additional A319/320/321.
e) Aero International was a good magazine until Rudolf Braunburg died and others took over. Since that time the quality went down to basically stating the official releases of the airlines, and the news are in my opinion not really of high quality. I know what other magazines write which possibly appear every week - and then it shouldn´t be too difficult for a monthly periodical to bring news of high quality. If I compare them with Airliner World I will always favour AW.