This is purely my opinion without much to back it up, but I'm always game for brainstorming new ideas.
I think you'd have a difficult time selling enough of either of those to quit your day job.
The second idea does exist in the form of mass produced power conditioner. I know you said yours would not be a power conditioner, but could you be price competitive against mass produced power conditioners with time delays? If not what extra value are you offering.
Last, I'll offer an idea for another product. It would be an A-B switching unit (you'll have to evaluate how feasible it is). It would need to have the ability to operate using a remote. And have both line level and speaker level switching capability and volume controls so you could level match. The objective is to be able to level match and switch between two speakers or any two sources, subwoofers, or preamps. I'm not sure if you could work it so you could A-B two amps with the same source and speakers, but that would be nice if it is possible.
In any case, I think you'd need to build some first units to test, photograph (for your website), and see what sales you can scare up.
I'm assuming you plan to construct these yourself as opposed to mass production?
If so, you may want to offer a standard unit which you keep in inventory and also have some custom options (were it would make sense) with a 2-3 week lead time.
Last, I think there is a market for working with the MiniDSP and integrating it into a hardware package. This device seems to have some great flexibility and I'm not sure the scope of uses for it have really been determined yet. If you could establish yourself as someone who could custom program it and/or interface with other hardware There could be a market for this.
Here are a couple of reviews and descriptions from AH members if you missed them.
http://forums.audioholics.com/forums/showthread.php?t=65313
http://forums.audioholics.com/forums/showthread.php?t=71464
I really haven't looked at this item, but the general sense I get is that it is very capable, but also a bit complex for the "average Joe". I believe if someone could reliably program it for the desired application and give the customer a simple way to "re-flash" or otherwise reset that programming if it gets corrupted, you may be able to come up with a viable business model for a one man operation.
HTH and best of luck!