The email is perfectly appropriate and not offensive. However it is a bit confusing and the clarity can be improved.
Specifically, your email does not clearly highlight the question your asking and it is easy to ignore or misunderstand the purpose (why you are writing) because there is a lot of other stuff in it. That other stuff is definitely good to include (I think the professor may like to hear it!), but your question gets lost in all the other text, especially on a quick glance.
Here is some advice on how to make your question stand out more clearly:
Put your question as early as possible in the email.
Make sure that there is a question mark after your question. This actually makes a bigger difference than you might think.
Therefore, below is my suggested edit to your email.
I hope you are safe and doing great.
I am checking in to ask: do you think I might still be considered for admission to your group? What is the expected timeline?
I ask because I have received a few offers from other institutions. Their acceptance deadlines are beyond April and expect the first round of admission results of (your University) will be announced soon.
Also, I found the interactive online learning quite helpful and once again thank you for suggesting me the courses a few months ago! I am taking courses on Power Electronics, Sensors and Motors (offered on Coursera by University of Colorado Boulder).
By the way, your post here has the same problem as your email :) You wanted to ask, "Is this an appropriate email?" but your question was hidden because there was no question mark. I edited your post to make it stand out more -- do you see how it makes a difference? When glancing at your post, now I can clearly see your question.