We have had a few requests, but it hasn't bubbled up to a high enough priority yet. Also, someone already released an announcement plugin that you can get at http://www.blesta.com/forums/index.php?/topic/3180-plugin-announcement-released/
Yes, after/during our planned refactor. I don't have an ETA.
Services are recurring in nature, so we wouldn't consider web design or development a service in the same respect. Unless you are billing on a retainer or something. Most people track hours outside of Blesta, and invoice for development work from Blesta. No service necessary.
I think we would need more information on how you provide and bill these kinds of services to get a good understanding of the issue. Yes, development work is a "service", but it does not typically recur for the same amount every x period (monthly for example), and so it doesn't fit well into what Blesta considers a service.
Do you plan to integrate PowerDNS into existing services, via other modules, or offer it as a standalone DNS service?