Re: Moving to Karachi
First and foremost. This late latif is sorry for not being able to respond back in due time. I forgot and then the fact that I’m not a very avid lurker around this particular forum, didn’t help much.
Coming onto your questions. Well, the 1st one is honestly a monumental task to get done with. Not entirely sure how to go on about detailing what has changed in Karachi in the past 10-15 years. But to get you within a certain ballpark of things, the changes/developments have been huge and majority of them for the better (According to my limited knowledge of being born and bred here). I’ll get you a few links that hopefully will help.
http://board.classifieds1000.com/Pakistan/Expat/expat_living_in_karachi
^ This link has some pretty amazing experiences listed by people from local as well as foreign shores. The guy Faisal however, I wouldn’t look much into. You’ll understand why once you carry on reading till the end.
http://www.findpk.com/cities/html/karachi.html
^ This one just has the basic details of what you’ll find here. It also has a list of the medical universities/hospitals around, which might come in handy for your professional goals.
Another link would be hitting enter to “Karachi pictures” in google images. Provides you with pictures as to what you’re in for or should look forward to seeing.
The most recommended places to live in would undoubtedly be Defence, Clifton, Bathisland, KDA. In order.
Apartments are east to get a hold of, studio or a one bed apartment could however be a major chore to find. 2 or 3 bed apartments are easily available, either for rent or for straight out purchase. Rents start from 15,000rs ($180) for a unfurnished 2 bed and go up till about 35,000 ($400) a month for a 3 bed. Prices however could differ from area to area. Add up at least a $100 in case you plan on getting a furnished apartment. Maintenance (Water supply, cleaners etc) charges are additional and come up to about $50 tops.
What to get along? Umm I’m not sure, because whatever I’ve needed I’ve been able to get it at Agha’s or Ebco. But then again, I haven’t managed to stick around abroad much so I honestly won’t have a clue.
As for Loadshedding. Here’s how it works in Defence and for me. We have two connections to two different grid stations. So lets say, KESC (Karachi electric supply corporation) decides to cut off supply in Phase 4, all I have to do to come back to life is to switch this tiny little rotatable switch that’s set up in say my store room and voila, I’m golden. What technically happens is, KESC doesn’t cut off supply on all the grid stations or area’s together, they’d be doomed if they do that. So jee, they do it one by one. So while Phase 4 has its electricity cut, phase 5’s is working for the hour and since there is a separate line coming from phase 5, my house in Phase 4 is all lit up. Now the best part, as the 2nd supply line is coming through your house’s line, you’re technically being billed for all the electricity you use so hence its all legal.
3 hours Loadshedding is all I’ve experienced in defence and in the summers, usually the schedule goes something like. 9 to 10am, 3 to 4pm, 9 to 10pm.
An hour max in the winters.
Irrelevant bit. There are a few danish/swiss couples running an institution for the disabled kids here in Phase 6. Yes, they’re legally allowed to go back to their own country whenever they wished to but don’t. On top of that, they roam around alone and at times with a shirt on their chest that has a green flag or 'Pakistan Zindabad" embossed on it.
Irrelevant bitx2. If by any chance you think you could be of any help to the institution, let me know. I’m sure/aware they’d like a couple more teachers.
Anything else, feel absolutely free to ask. 
Cheers.