There are some very reasonable OS fares to Central Europe via VIE, connecting on to VO (Tyrolean) props to the likes of BUD and PRG. They also seem to be pushing their new A319 service to further East and South, so have a look out for that. ebookers and onlinetravel seem to get the best fares IME. Try and get the NG-operated LHR-VIE flights for the amazing food!
It's also worth signing up to OS's 'Airmanager' reservation engine. It's a relatively poor interface, but allows to you select 'all *A' itineraries, and quite often significantly beats other *A airlines' own websites for pricing. Otherwise, virgintravelstore.com is quite handy, as it lets you specify (in advanced mode) *A itineraries as well.
Otherwise, there's actually a small benefit with the mileage changes: LO's (often very cheap) Q fares are now 1x mileage instead of 0. I've seen a lot of Qs (around £150) for LON-KRK (usually LGW-KRK, but I'm sure you could get a connection via WAW to get the miles). LO's own website lets you contruct some 'imaginative' itineraries, too, so it's worth playing about with.
For SK, you could try and get a routing via both CPH and ARN to somewhere like HEL, to get a 3-legged run. Do watch out for SK flights operated by Blue1 (not yet *A) and AirBaltic, though.