737 rosters depend on base. As the 737 takes over it is doing more and more 'mixed model' flying, ie charter as per the 757 with some of the low cost scheduled flying too. I am MAN based on the 737 and my rostered flying out of there mirrors my old 75/76 roster.** However, if you join one of the 'original' 737 bases (CVT, BOH and DSA) then you will do more of the scheduled routes, with a mix of charter.
As far as commuting goes, LGW has to be best, but MAN is a close second. If you live south of MAN you have the choice of EMA, with LPL not being too far away either. Plenty of lo-cos at MAN, EMA and LPL, not sure on flights to Scandinavia though...
PP
** edit to add that it mirrors the shorthaul flying on my old 75/76 roster, obviously not including longhaul!!