No worries, but a few questions on the Browlock popping up. Were you logged into your account at the time? Do you have/remember the link or post which caused this? What was the address of the sender of the email?
Most of this applies to Windows, as actual infections which lock your computer from starting are extremely rare on Mac, less so on Windows. So far encrypting malware is only Windows based too.
1. It the Mac is shut down will the countdown clock be stopped - I believe it depends on the ransomware, but mostly no (it really depends on whether the infection keeps track of time).
2. does the timer have any real effect - It depends what kind of ransomware it is, if the ransomware is cryptolocker then yes, very much so. The timer means you can pay less to get your files encrypted. As for most ransomwares, which are just fakes, the timer has no effect, apart from a few which delete themself after the timer finishes. The timer for the fake ones can take a long time, so I wouldn't rely on that, rather remove it via Hitman or similar.
3. With the Mac shutdown will if halt any of the infection spreading - If you happen to notice files are being encrypted and you see a suspiciously named file running in task manager then yes as it will stop the encryption process until you start the computer up again. Otherwise, these infections do not spread.
4. Will this virus spread on my home network and to dropbox - Same as above, an encrypting ransomware will affect networked drives and dropbox (although you can restore previous versions on dropbox) and encrypt all it can find. Fake ransomware does not spread.
5. I can use my Mac normally, access all files and programmes except Safari and then only on my account, on other accounts it too worked fine. Does this mean anything - Fake ransomware will completely block you from being able to run anything, it runs on startup and pretty much replaces the desktop which you normally see. Encrypting ransomware will not stop you running programs, but you will not be able to access your files.
6. Will this get worse when I don't pay or don't remove it. - Hmm, well not really. If you want your files back then you will have to pay almost in every encrypting ransomware, though not all will get you your files back. As for the other fake ransomware then paying will not get you anywhere most of time, or there is no need.
7. On the advice of another website I when into Safari options and clicked all the option boxes and pressed restore. Immediately everything seem to be working as normal. Could the virus now be removed? - Yup, browlock makes no changes to your computer. It only locks your computer.
8. How can I tell if the virus has gone. - Well it's best to run your antivirus and Malwarebytes and remove anything they find.
9. I downloaded F-Secure protection and ran a scan which found nothing but would it.
10. If the virus is still there if I copy files and move them to another PC will I bring the virus with it - Nope, as long as you do not copy over any executable files then you will be fine.