I need to perform an export/import of a subsite between environments. Is it ok if I use my personal account (which has local admin) to do this, or should I use a service account such as the sp_install account or sp_farm account?
you need to be in Administrators group on the local server. I presume your referring to powershell command.
another method would be:
save site as template on sharepoint.... if its a publishing site, on the web.
on the source site:
site actions -> manage site features -> turn off publishing feature.
you should now be able to see save site as template. click on that and save site as template with or without content.
once complete it will display a link to the gallery where this template is stored. click on it. in the library click on the new template and save it to your local drive.
turn the publishing feature back on the site.
goto the site you want to migrate the site to, do the same again and disable the publishing feature. goto site templates list and import the saved template -> activate -> create a new site and you should see it in the list of templates to create from. once created enable the publishing feature.
on both site collections you need to make sure that both have the exact site collection features enabled. they need to be identical or it will fail to create the site.