Swimming is a good work out too you dont need to be a good swimmer just Walk, Jog, Jump, Kick your legs inside the water - repeat. Its simple just let your body moves cos it burns calories. Start slowly and gradually increase the duration and intensity of your workouts gain strength, improve flexibility, and slim down.
I have joined the weekly Aqua aerobic / bike class and its really fun, you can try :)
Ok here a thing...do you actually believe that his children and his parents are going to welcome you with open arms? To be realistic, the children may very well hate you for the rest of their lives for disrupting their home life.
RE: Distance...
LDR works if two are willing to work it out, otherwise friendships on a long distance is fine too.