From Shared to Dedicated Hosting (Domain Mapping?)

Hello,

I am running WordPress MU on shared hosting. I am going to built whole system 100% and then move to my own server. Are there any plug-ins, which may cause any problems while moving? For example, if now (on shared hosting) I activate domain mapping and 2-3 users map their domains on nameservers of my host, will I be able to move them to my server too?

Are there any ways to change domain nameservers while moving to other servers?

I don't know how clear is what I have written here, so I will make one example:

My (Blog network administrator) user creates blog - something.blog.com and attaches a domain something.com with nameservers of HOSTING, which I am using too (because I am on shared server). When it is time to move to my server (which will have it's own nameservers of course), will I be able to change this user's domain's nameservers without any trouble or not?