Up to 90 days for tourism and business purposes.
yes
No need for a visa, as the UK is a participant in the Visa Waiver Program.
In the way of actual paperwork, none apart from the marriage license. The UK citizen comes in on a visa waiver and you can get married in the US. For the US citizen to get to the UK, that is where the paperwork comes in. You both need to go to the UK embassy in the US and apply for a marriage visa for the US citizen to come into the UK. The US spouse will then be able to work straight away when you get to the UK also based on that visa.
Absolutely no! You have to obtain UK visa before going to UK
If you are not a citizen of the US or Canada, you must have a US Visa to travel in the US.
The tourist visa is for a set time frame. You could get married, but the person would have to return home until they can get a residency visa.
Yes, the British citizen comes over on visa waiver. You can get married. If you both plan to then go to the UK straight after, you will then need to apply for a spouse visa for the US citzen at the UK/British Embassy in the US. This will allow the US spouse to come to the UK and also work straightaway.
You dont need a visa. Its part of the Visa Waiver program between US and UK
No - you can enter the UK for 90 days without a visa for tourist purposes
If you get the UK work visa then the work permit is not given to US so you need a work permit for US.
Nope it wont effect
A person with an expired visa must apply for a new visa prior to applying for US citizenship. You can't apply when you have an expired visa.