I use and have used 1&1 for a few years now, and have found them a very helpful and obliging company to deal with. If you have any questions or problems, then I would suggest that you contact them direct. Because it would depend on how and what you want to download. I have no experience of Abode Muse, so I wouldn't now the actual answer you are seeking.
Another point worth mentioning, is that they do have 'special offers' on now and again on packages, and the discounts are perhaps worth considering.
Shouldn't take long, but remember that it would most likely depend on how quick 1&1 gets paid.
Perhaps worth mentioning, that 1&1 will send a reminder abour 4/6 weeks before renewal of domain is due,whether that is one or two years of domain, and will take funds from the source you have provided, unless you notify them before re-payment is due. I find this very helpful, because it save you forgetting, and perhaps losing the domain.
If you go to the Nominet site, there is a UK domain checker, which will tell you if a domain as been registered in your name. EU domains are a different system.