Yeah, I think DB would be too much of a stretch for me- mainly because unless you can afford to live right by the ferry, the bus/ferry combo would be a PITA when it's really hot/ raining etc. Also, the way they charge extortionate amounts for the permits for those flipping golf buggies sticks in my craw. I do know lots of people who love it there though. It's just not for me.
Re PFL, actually it's probably one of the more pedestrian friendly areas (flat, has pavements), but you're right that there's not a whole lot to do there. There is a public park by Bel-Air, soft play nr the Belchers, and there's Cyberport, but actually, most people "hang out" either in their complexes (Bel-Air is the huge and most luxurious one with great facilities. Scenic Villas and Victoria Gardens are older but also popular, better priced and have pools/ playgrounds), or at their clubs. Alternatively, there are some really well priced University of HK apartments (Tam Towers, High West, Middleton Towers etc) which are a bit retro, but huge - no facilities but you can join the Stanley Ho Sports centre or the Meridian in Cyberport to access pools/ gym etc.
Re mid-levels, if Aberdeen is a pre-school option for you (assume you mean Woodland Harborside/ Wah Fu), then where I live (Bamboo Grove) could work, especially if you want a more urban setting- it's in Mid-levels east, right by the start of Wan Chai. There are tonnes of kids here of all ages, good mix of nationalities, good management. Peak School (ESF) catchment. It isnt as plush or green as Bel-Air but the apartments are bigger and there is traffic-free outside space for kids to ride their bikes/ scooters etc and children can "play out" with friends, without actually being outside the complex, so very safe. Aberdeen looks like a long way on a map, but actually only 20 mins through the Aberdeen tunnel. Similarly, Repulse Bay is do-able from there.
If you have a club membership (so dont care about not having pool in your apartment) then some of the colonial buildings are larger and better priced.
Do you have an agent assigned to you? If not, i can PM you a recommendation.