Breathers & Nissan Snorkel???

[10G]

On a 2013 Y61 3L CRD do we have gearbox breathers? Is it a good idea to fit breathers, or aren't they really necessary?

I've not done anything with the front breather as it goes half way up the firewall anyway, should I extend it?? Where have others mounted the front diff breather?

Rear diff, I have extended that breather, out & into & up to the top of the fuel filler cavity. Where have others placed their rear diff breather???

And the stock Nissan GU ex Airtec snorkel. Do I need to do anything to it to make sure it's water tight????

Thanks for any help.