I'd suggest you to move your accounts slowly.
Move 3 and see how they behave for 1 week, then move 2 more and see how it goes. In a month you'll have them all moved, and if something goes wrong at least you'll know from a few of them instead of having to deal with all 10 at once.
I see you are used to unlimited resources and are afraid of limits. But believe me, everything has a limit Your current host just take responsibility of them and make sure they'll all be above the sum of all usage,... or oversell and offer you what's available, since unlimit also means they are not promising anything.
Since you know how much you are currently using, just get the plan that best fits you, and if it's not enough just get a bigger one.