i was never checked upon flying back to DR until my last trip to europe - i had to present residence card upon check-in. macy, your possible route will depend on preferences: you want the cheapest? the fastest? most luggage? least plane changes? i flew to london with iberia, from SD via madrid. my family usually does that or air france, also from SD. air france has the biggest luggage allowance so it pays off if you travel less frequently. 2x25kg is the best you can ever get and is a real blessing. iberia tends to be a bit cheaper. you could also fly via USA, you do not need a visa. or start in POP, fly airberlin to dusseldorf/munich and then london. i personally prefer flying all the way with one airline: in case of delays they have an obligation to help you out with the next available flight.