With Medina: It can pop out monastaries in 3-4 turns from hammers alone and working extra coast gives a significant boost to commerce. With bugged 1 pop for 60 hammer whips, that would be worthwhile, but at the 1:30 exchange rate we are really better off just working the abundant high hammer tiles.
Look at it like this: At 50% research (our break-even point) we get just 32 beakers a turn - that's with the 5 coastal tiles at Medina - now without those 5 coastal workers we'd bring in only 20 beakers a turn. In short, a giant medina increases our research by 50%. I'm tempted to say we should grow Medina even bigger, right up to size 14 or so where it can work ALL the coastal tiles AND run 3 specialists (14 is also Medina's health cap atm and adding 3 chariots would increase the happy to 14). Once a city is at size 14 whipping isn't worthwhile at all (except bugged whips).
So Medina should be grown until it's working every coast tile, every good hammer tile and has 3 specialists (which alternatively can be put on the plains forests).
Overall go easy on the whipping, whipping wont give us any extra commerce, unless it's whipping in libraries or marketplaces (a market is about the only thing I'd consider whipping in at Medina).
Taking a close look at the other cities...
Najran is one city I'm not sure quite what to do with, it has a library now and will soon have a theatre. It has a silver mine but working that will kill growth. I think we should grow it to size 9 at which point it works the deer, the farmed plains, all 5 coastal tiles and finally the silver mine, leaving it basically stagnant at +1 food but bringing in a good amount of commerce. Also all the (non-deer) forest at Najran should be chopped (eventually, anyway), it doesn't have the food surplus to work any of it and the other tundra hill can just be mined (which will definitely kill the food surplus). Note there's no need to improve the tundra river banks, 2-0-1 tiles are NOT worth working (so the same goes with any ocean tiles too, workers on ocean are bad). So Najran really needs no more worker investment until biology (except to chop the forests - good way to get temples).
Basra (the fisholess city) should be left alone to grow until it's working all the coast (or hits the natural happy cap anyway), working the quarry will complete the buildings it needs.
Kufah should be whipped since it has NO production (and it's best to keep it that way, by working only cottages rather than the hill). It should probably be whipped every 10 turns like clockwork. Monastries are good there, it needs to apply cultural pressure and it'll be a good place to whip out missionaries.
Mecca and Damascus should both be treated in much the same way, always work any 1-3-x tiles but don't work the plains hill mines unless a wonder is being built, basically between wonder builds food should be maximized (within reason) so that wonder build speed is maximized. Don't whip either of these cities unless it's a real emergency, whipping them wont improve wonder build speed one bit.
One final thing which I SHOULD have thought of during my turns:
Switch out of organized religion. This will save us 4g/turn and we aren't building any missionaries at the moment nor for the forseeable future and we'll have monastries anyway.
Look at it like this: At 50% research (our break-even point) we get just 32 beakers a turn - that's with the 5 coastal tiles at Medina - now without those 5 coastal workers we'd bring in only 20 beakers a turn. In short, a giant medina increases our research by 50%. I'm tempted to say we should grow Medina even bigger, right up to size 14 or so where it can work ALL the coastal tiles AND run 3 specialists (14 is also Medina's health cap atm and adding 3 chariots would increase the happy to 14). Once a city is at size 14 whipping isn't worthwhile at all (except bugged whips).
So Medina should be grown until it's working every coast tile, every good hammer tile and has 3 specialists (which alternatively can be put on the plains forests).
Overall go easy on the whipping, whipping wont give us any extra commerce, unless it's whipping in libraries or marketplaces (a market is about the only thing I'd consider whipping in at Medina).
Taking a close look at the other cities...
Najran is one city I'm not sure quite what to do with, it has a library now and will soon have a theatre. It has a silver mine but working that will kill growth. I think we should grow it to size 9 at which point it works the deer, the farmed plains, all 5 coastal tiles and finally the silver mine, leaving it basically stagnant at +1 food but bringing in a good amount of commerce. Also all the (non-deer) forest at Najran should be chopped (eventually, anyway), it doesn't have the food surplus to work any of it and the other tundra hill can just be mined (which will definitely kill the food surplus). Note there's no need to improve the tundra river banks, 2-0-1 tiles are NOT worth working (so the same goes with any ocean tiles too, workers on ocean are bad). So Najran really needs no more worker investment until biology (except to chop the forests - good way to get temples).
Basra (the fisholess city) should be left alone to grow until it's working all the coast (or hits the natural happy cap anyway), working the quarry will complete the buildings it needs.
Kufah should be whipped since it has NO production (and it's best to keep it that way, by working only cottages rather than the hill). It should probably be whipped every 10 turns like clockwork. Monastries are good there, it needs to apply cultural pressure and it'll be a good place to whip out missionaries.
Mecca and Damascus should both be treated in much the same way, always work any 1-3-x tiles but don't work the plains hill mines unless a wonder is being built, basically between wonder builds food should be maximized (within reason) so that wonder build speed is maximized. Don't whip either of these cities unless it's a real emergency, whipping them wont improve wonder build speed one bit.
One final thing which I SHOULD have thought of during my turns:
Switch out of organized religion. This will save us 4g/turn and we aren't building any missionaries at the moment nor for the forseeable future and we'll have monastries anyway.
. It would have given us more if we had more variety of tiles to switch and use multiples of 4 research. Ah well.
So I gave it to him.
I can't believe I didn't think of that...) Also agree that Kufah should work nothing but cottages and whip for production (it's not quite doing that now). 
.
Next person should probably switch out of that immediately.
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