You should better keep the current domain working for a while so you can redirect all readers from current domain to new domain using JavaScript or plugin so your readers from current sites can aware the new domain.
Remember add canonical meta tags to all your posts on current domain target to new domain so crawlers from search engine will index the posts on new domain instead.
GA will not be affected if your GA account is a hosted account.
You will have no problem with JetPack.
]]>You can export and import the content from the current domain to the new one
You should better keep the current domain working for a while so you can redirect all readers from current domain to new domain
This makes no sense if it’s the same physical hosting, just a name change.
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