Quite possibly yes, however choice of domain registrar and VPS provider is in most cases a purely personal choice. Digital Ocean works well. name.com should also as long as they allow you to set ‘glue’ records - something that 99.9% of registrars do, so yes you should be good.
Multiple domains, as in receiving email for multiple domains while the web hosting and other services are run elsewhere, correct?
MiaB is designed to run all of the DNS for the domains that it hosts. Sometimes that can complicate things, or simplify things. You have to look at your current DNS set up and decide if you want to keep it in place, or allow MiaB to take it over.
If you keep it in place, you will need to set the MX records for all of your domains to point to MiaB and you will have several additional DNS entries to manually enter into your current DNS.
If you allow MiaB to take it over, you will need to change the name servers at your domain registrar to the MiaB name servers and create custom DNS entries in MiaB for your web sites and other services. The one problem with this IMHO is that you then introduce a single point of failure for all of your domains by not having secondary DNS, which is an additional step to achieve so it is not a major problem to deal with.
Not SPECIFICALLY. But following the installation guide and searching the forums you should be able to determine the steps if you have any familiarity with Domain registrars, name servers, MX records, etc. If you are completely unfamiliar with any or all of these concepts, help is always available in this forum. I can always be reached by PM if you need assistance.