I personally think you should get away from the computer and try to learn about the basics of design in general. Typography, grids, colour stuff like that...

I would probably stay away from just learning a software app or browsing websites to learn design. If you want to learn how to become a better visual designer, the fundamentals of design are what you should brushing up on.

Typography, grids, and colour theory are your basics. Start reading the primers that cover that. Most of what you see on Dribbble, while (may be) very nice, occasionally lacks understanding of the fundamentals and copying them would be a bad way to learn.

You could probably learn a lot from print work alone, even if your work is primarily on the web. Also, the fashion industry tends to be more innovative in it's use of typography and grids, so there is a lot to learn in that space.

UI components aren't a good way to start. Everyone can learn how to make a box. The best designers build systems not boxes.

Yes, it's possible to be a hybrid, but it will take time.

As a former developer who now heads up a design team, my advice would be to pick out the elements of design that interest you and that you feel you have a good grasp of, and start from there. For me it was typography. There is something specifically systematic about type and how it is arranged on screen. From here I explored vertical rhythm and grids and developed an understanding of hierarchy and building pages. I still work mainly in UX and wireframes, and specialise in web applications - this being an area where a more systematic style is beneficial - but I can stretch myself if need be.

I found the hardest part of being a designer is taking critique - as a programmer something works or it doesn't, but as a designer everything is more subjective. It's a skill that is taught as part of a design education but coming into the industry without a formal background made learning to take critique on the job and explain my reasoning especially challenging.

Just make things. All the time.

I'll throw my two cents in since this is pretty much what my career looks like. I have a computer science degree, I started off in "traditional" software development roles, and I'm now a designer at GitHub.

Even during college and my first development jobs, I realized I had an unusually high interest in visual design and what would come to be known as UX. When I worked on my own projects, I naturally wanted to handle the design side and eventually I became relatively proficient at it.

I decided to go independent after a while and I freelanced for ~7 years. At first I prided myself on the fact that I could do everything. I could do all of the backend coding and I could make a nice UI. Over time, I realized that I could never be really good at everything. I decided to put more effort into improving as a designer while not completely abandoning my tech chops.

So, back to your questions. My opinion is that yes, it is possible to be equally good at everything on the spectrum as long as you're ok with the skill level across the spectrum never being super high. My colleague Kyle Kneath has a fantastic visual explanation of this idea. (Jump to slide 33 of this presentation)

As for the first question, learning how to use Sketch (probably a better use of your time than PS at this point) is certainly helpful. What I like to tell people looking to improve at design is this: start seeing the things around you. We all look at things every day, but most people don't see them. When you see something you like (whether digital, physical, etc.), ask yourself why you like it. Is it the colors? The tactile feedback? The tone of the copywriting? The subtle use of animation? Someone designed that thing. Put yourself in their shoes and ask yourself how you would have designed it. What would you have done differently and why is their version superior?

If you're interested in UX, I assume you have strong empathy skills. If you have decent developer chops + natural empathy + a desire to improve your visual design skills, you will be a very valuable member on any team. You don't need to attempt to become world class at everything, but follow what you're naturally interested in and you'll be in a great place.

I didn't mean to ramble this long. Hopefully some of this is useful.

You might want to check out this post: https://news.layervault.com/stories/25360-ask-dn-how-can-a-developer-design