For starters, once again my compliments on the look and feel of this thing.
I share the Solid vision, but also your doubts on the initiative. I’ve spent a lot of time discussing scope and positioning of the solid project, most recently in this thread. The complexity is one thing, but it comes with the feeling that solid project is working all over the vast scope of the initiative and therefore it’ll take years for things to reach maturity and production-readiness.
My interest is in combining the best of both worlds of the ActivityPub Fediverse - which is linked data-based and does have a whole bunch of production-ready, widely used applications already - with Solid’s strength: full control of the data you expose (see also: How Solid and ActivityPub complement each other best).
But I find it hard to lay my finger on just this core feature, Solid’s main USP (ostensibly). From that perspective I intuitively am more attracted to Encrypted Data Vaults with its layered and modular architecture.
But things can change and improve, and that’s why I’m here 
So I see a benefit and opportunity for your application to be both Solid in terms of data storage and well-connected, accessible in terms of ActivityPub support. There has been a project called CloutStream (now dead) that was intended to be the LinkedIn for the Fediverse (and could also be part of the IndieWeb at the same time). I’ve seen many people state the desire to restart this or a similar project. This will be a popular project I predict.
(I’ve been thinking to doing something like that too (after finding react-resume), but my current hobby project is innercircles.)
Anyway, the fediverse offers the social features you want (subscribe, follow, interact), and the ability to federate, set up your own instance, or choose an existing one to host your account / blog / CV. There are a lot of personal blogging softwares in the making, and adding a CV to this concept would be a natural fit.
I would not continue the XML path. I’ve been deeply involved in XML dev for a number of years, but right now it is mostly used in enterprise contexts and elsewhere we have JSON et al.
Regarding offering your CV functionality… this seems a complicated path. If you develop the core functionality as a JS library, then integration in various platform (e.g. wordpress) becomes easy (and can be done by others too). Additionally you can have a server software that can be self-hosted and for which you have your own instance to which people can subscribe. You can then either allow [username].my-cool-domain.name (requiring DNS admin on your site, or cPanel / whatever automation) or just my-cool-domain.name/[username]