Omitting Jumuah Salaah

Q: I work for a company where I luckily get my break by another colleague from 1300 to 1400 where I perform jummah, but I get this break from a Muslim brother. So I asked him to give me the break every second Friday at 1400 so he can attend jummah one week and I can attend the next week? I cover one site only and he works for my company. At the lunch breaks he relieves different people throughout the day. Is it okay for me to do that, otherwise he will end up not performing jummah at all?

Man saying "the next three women I marry are thrice divorced"

Q: A man said 'the next three women I marry are thrice divorced'.

1. If the man marries a woman, the divorce will automatically takes place, but if he marries the same woman again, does divorce take place?  

2. Is there any way around this if divorce takes place, like getting somebody else to marry on your behalf?

3. If a man says to a woman who is not his wife 'I give you one divorce'. If they get married does talaq take place?

Irregular bleeding

Q: A woman got her periods, however the flow was exceptionally light and only lasted 4 days as opposed to the usual 6 days. Also the usual symptoms that come along such as period cramps were not experienced. It has been 10 days and she has gotten her period, this time it is normal unlike the previous haidh. However should she consider this haidh or istihadah?