The primary distinction is:

1. A theme implies a ready-to-launch WordPress theme with design, back-end functionality, and anything else you might need (according to the theme author's discretion). "Theme" can be roughly equated to "plug-and-play" in the WordPress world.

2. A framework is a set of tools to assist in building custom themes rapidly by handling common challenges ahead of time. "Framework" can be roughly equated with "toolkit".

HOWEVER.

WordPress is an enormously popular, extremely accessible platform, which means that not everyone who builds for WordPress actually A) knows the difference between a theme and a framework, or B) actually did a good job of implementing anything that's promised.

That means that for every high-quality, no-hassle theme or framework you'll find, there are dozens more that are fragile (e.g. can't stand up to even light customization) or just plain terrible (e.g. full of security holes, silenced warnings, bad practices, etc.).

Popular frameworks like Genesis have large contributor networks, which cut down on poor quality and security risks. But for a non-coder, the learning curve may be a little steep.

The best solution may be to evaluate the cost of getting your current theme audited for quality by a professional coder with a good reputation in the WordPress community. I'm not familiar with the theme you're using, but it's possible that it's a great theme that's well-built. If that's the case, you can keep using it even if the theme creators were to suddenly disappear (though not for long, as there's always a need to modernize themes as WordPress matures and PHP marches forward).

If the theme is NOT well-built, consider having a pro build something quality that's specifically suited to your needs. This costs money, but you have to weigh that against your revenue (and the potential loss of it if your DIY site collapses in on itself unexpectedly).

Otherwise, do your homework and read reviews from the users of the various themes and frameworks you're considering. Contact the positive reviewers directly to determine how closely your level of skill and comfort with WordPress resembles theirs. That's important, because what I can do comfortably with WordPress (after a decade of building custom themes from scratch) will be very different from someone who's only comfortable using the theme customizer.

Sorry if this is a little overwhelming; this is a big topic with a lot of pitfalls and challenges down every path. It ultimately comes down to whether you'd rather spend time or money to solve problems, and which will ultimately end up costing you more.

If you'd like to go into the specifics of any of this, or if you want to discuss your theme in particular, hit me up for a call.

Good luck!