I know you're concerned at the speed of development but I urge you to reconsider doing your updates in one SQL statement. Why?.. Personal experience.
When I first got into PHP / Mysql years ago I wrote the biggest and best code for my site.. but I couldn't figure out why certain pages were so frustratingly slow compared to others. I put it down to my computer (which was running the wamp setup) not being up to the job. Only when I turned on mysqls query log did I realise why it was so slow. Some pages had 200 queries running and it was grinding down the mysql server. I certainly learned a lot about sql optimization that week! That was for one user - me. Imagine that multiplied by a few thousand users and it will crash even the most powerful servers.
As for the suggestions, yes all of the suggestions put forward will allow you to do what you want. You'll need to make them fit in with your code so to speak.
My helpful sig is on vacation trying to loose some weight. It got a bit fat and caused a few problems but it will be back at some point!