Demand I think is there as more companies are seeing the value of it. I used to run a UIUX team in my past company with about 7 UIUX designers in total. 3 on contract (2 Indians + 1 Filipino) and 4 local staff.
Prior to me leaving the company, I was looking for a UIUX lead and it was never easy getting one.

First of all, here are the usual break down of skills:
- I see in the market, a lot of people heavily strong on the UI side of things
- Not many have UX skills, whether it is from user research, conducting workshops with users and understanding the global nuances

The other I see is the lack of tooling knowledge, like understanding what is a design system or using design systems. Most folks tend to just stick very individually whether it is using Sketch, Figma, Adobe XD and others.

Another skill lacking in the market is actually on language, meaning writing the right kind of text for interaction to make UX easier.

Overall, those who excel in all of these skills above and more, tend to earn about RM25k in the market and more.

Here is a link I normally use as a reference in the past, from design system to job role and description as well as how processes are run.
https://dbsbank.design/

A lot of roles have good pay, it all depends on your skills/experience/knowledge

Yes, you can be focused on just UI design as well within the roles. This means your focus would purely be on the graphical side of things which means you need to have a portfolio of designs.
You can design mobile apps, web pages, banners, promotional materials whether it may be digital or physical, internal newsletters, external newsletters, and many many more.

Yup self taught are quite common as I have seen people with degrees in accounting and finance who decided to go the path of UIUX.

Language = Conversation UX design

For example, on a mobile app you have a text which says, "To confirm your order, please click on the confirm button below". This is bad UX conversation writing because at any point if the button is moved, the text would have to be changed as well (additional work).

Another one would be to have instructions in conversational and layman instead of overtly hypercomplex.

But when it comes to coding, there are those who focus on the field of web design that they have knowledge of HTML5 coding, mostly for the CSS design parts.

Whilst you don't have to know how to code, you need to know what might be the technical limitations. For example, some corporates may not necessarily use HTML5 CSS as they use publishing software for the web pages. So you need to know what are some of the limitations in technology before designing the overall website UIUX.
Then you need to also take into account if the company has a design system in place or a brandkit which you would need to follow accordingly as well.

You just need to have the skills as well as two of my last graduate trainees were from comp science background.
They had 1-2 years experience but went through the graduate trainee program at my last firm.

Honestly when it comes to UIUX, it is all about your portfolio and your abilities. Most of the time people favour a lot on the UI skills because that is one you can opt to build especially in school days and all but when it comes to UX, its a little tougher unless you get internships at places and learn the UX related knowledge. Skills can all be learnt whether it is through online courses and classes. Just build your portfolio and then start looking out.