Is 3.5k RM acceptable salary for fresh graduate foreigner in KL?

Good enough to Live in Malaysia.

Glad to hear you live a healthy life.

Yes RM3500 is fine as a starting salary. Many people earn a lot less than that but they often live with their parents or their wives earn a salary too. Accommodation-wise you might be able to find a small studio but if not then a room. Of course if you can get a higher salary, closer to RM5k would be better.

Which part of KL will you be working?

That's about what my niece earned as a fresh graduate, so it's in the range that you should expect. As mentioned housing will need be kept to a reasonable amount on that salary. Don't expect to live in a 5-star condo with rent being RM3K, you may even have to consider renting a room in an apartment. My sister-in-law has an apartment building that she rents out 4 different 2-bedroom apartments and in 3 of the apartments there are FOUR girls sharing the apartment (2 in each room). But they're only paying RM150 each to live there (she rents the apartments out for RM600 per month, but before anyone asks she NEVER has a vacancy at that low of rent).