Are these two plans safe to switch to now?
Yes, I think so. I just switched to Mad RingPlus a couple of days ago and there were no glitches at all. Hopefully that is (has been) the case for everyone who made the switch.
Looking at the setup of the two plans, it seems that you can switch between them as often as you like and any change is effective immediately.
I guess this means you can get unlimited data.
Does Mad Daily Cent includes 100 minutes and 100 MB data every day at no additional charge?