(1) I do not want to work on other people's projects, as I am an Idea guy. I can come up with all sorts of great, solid game ideas; and I want to make them (one at a time, of course).

(2) I was 100% convinced that I needed to make an HTML5 game, because I truly see it as the future of gaming, on the desktop anyways.

(3) However, I feel like I am making a pretty hefty sacrifice by switching from HTML5. It's been a dream of mine for a while to make an HTML5 game, but without a team to back me, perhaps it's nothing more than a dream?

Just to point out a few things:

1. It's great that you are creative and have many great ideas, but so does almost everyone else in this industry. Why you don't always see these great ideas in the finished products have to do with several factors both technical, mechanical and esoteric. Not to mention the fact that people are generally their own worst judges.

2. No single language is going to be the future of gaming. But do learn as much about it as possible, and then you'll see if that'll be enough or not. Also, have in mind that the actual mass-production of services to the public is quite far removed from what you see in today's technology expos (if those are your basis for predicting the future, as some people seem to think).
Availability != visibility or demand. For instance, there's a whole line of logistics that must be in place before 100% server-based AAA gaming can be viably offered to the audience. Especially when PC DVD's and Consoles are already so amazingly successful.

3. If you are concerned about learning more than 1 language, then tbh I'm not sure game design is for you. Have you actually made a successful game yet, using only HTML5, CSS and JQuery? You "sort of know what you're talking about", but what have you actually made? Game designers are arguably some of the most elite programmers out there. Successful AAA game design is often severely multi-disciplinary and requires an understanding of at least the basics of a multitude of different tools, subjects and (possibly) languages.

My advice to you is this:

Try to find some intrinsic reason for designing games. Game design isn't just a means to an end, it's a massive industry that requires all of your attention and focus, because you're going to need to learn tons and you're never going to stop learning. Perhaps you're better suited for game marketing and distribution, who knows - you'll be able to decide what goes and not, and you don't need to know a single line of code. All you need is the money to invest (which is itself an achievement).

But if you do want to design and develop, then just take it one step at a time. Eventually you'll know enough about your first language(s) to learn the next one more easily, and the next after that. But don't speculate on those things now. If you think you know enough about the future, you don't know enough about the future.

The future is a cascading fireworks of emergent events, not some predefined function of a few simple rules.

I think where you might be hitting a wall is trying to use technologies like CSS. This type of web tech does not offer enough flexibility for pseudo realtime games (I personally also find it completely defective for normal web pages too). So I suggest looking at "coding" languages as opposed to markup (layout) languages.

In my own experiments, I've found CSS to be quite a boon, particularly for UI, in my HTML5 game experiments. Usually using styled HTML elements for the UI, which can be overlapped on top of the Canvas with transparency, performs better than rendering the UI elements using draw calls on a canvas. It makes it easy to change the style of your UI, or to make it skinnable per-user. You can also then leverage all the normal javascript libraries, like jquery and friends.