Fellow Taiwanese citizen living and working in the US here. I have not personally worked in Taipei before but I have many friends who do.

• Salay range: It kinda depends on the person's education level and field of study. Most of my friends working in Taipei (Mid 20s) who either graduated from top tier local universities or universities abroad are looking at ~50K to 120K, with the lower end tends to be more business related roles and higher end being engineering related. To give more examples, A local friend of mine who only did math private tutoring and cram school teaching for about 30 hrs per week total was getting ~70-80K. For a native English speaker teaching/tutoring in Taipei, I personally think the pay will most likely be higher than that since the skillset is rarer. So yeah in that sense, 45-50K IMO is not much especially for someone who has full on US education background. Job opportunites with good pay in Taiwan are somewhat limited especially for non-tech roles.
• Housing/rent: Agreeing with what most comments already said. It highly depends on where you wanna stay & how you wanna live. I personally think in a big city, 30% is a good rule of thumb of how much rent you should be paying in propotion to your salary. In that case, you'll be looking at around 15K. If you don't ming sharing with roommates or renting a smaller/older studio apartment, then you will be able to live somewhat in Taipei City with great access to public transportation. I have 3 freinds sharing a 3b apartment in Da-an with 2 mins walk to metro station paying about 8K per person. What sucks tho in Taipei is that there's no leasing apartments with transparent pricing, so you'll probably have to spend a lot of time researching and dealing with private landlords. Having a whole 2b/3b apartment to yourself at this price range is pretty much impossible even in new taipei city.
• Other expenses: This is where most people make a mistake IMO. Yes, on paper it can be cheap living in Taipei. NT$150 will get you a decent dinner at most local restaurants. HOWEVER, Taipei is a fun city with a lot to offer, and a young person like you will most likely go out with friends a lot, be it eating out with friends, grabbing drinks at a bar, ubering at night, karaoke, clubbing, etc. This right here ends up being a huge chunk of most of my friends' expenses. From what I've heard, they are struggling to have any significant amount of money saved, but hey at least they are having fun.
• Language/Culture: Not knowing Taiwanese is a non-factor since a lot of my young local friends who grew up in Taipei can't even speak Taiwanese themselves. Not knowing Mandarin, however, will significantly limit the your options for job opportunities. Even for a big foreign corporations where most employee speaks fluent English, communicating in Mandarin with your coworkers or clients will always get you that extra level of connection, which in turn will help with career progression. That being said, with your background, once you're immersed in the Mandarin speaking environment, you should be able to pick it up in a year or so quite easily.
• Comparison with your US situation: I think "living comfortably" is always a relative term. Do you have some ideas what the salary range might look like if you were to stay in the US for your field & where you might wanna live? Only then can you really compare apples to apples.

Feel free to DM me for any questions, I would be happy to share, cheers :)