The part that is of interest to me is that Sporeans will be able to move & stay in ASEAN without all the red tape.
Your interpretation of AEC and the above benefit to Sinkies is wrong.
AEC does not give automatic right of abode to Asean citizens in countries other than their own.
If your interpretation of AEC framework were correct, Sinkieland would become the most preferred destination for Malaysians, Pinoys, Vietnamese, Burmese, etc.....(or Ah Tiongs and Ah Nehs who pay for citizenship in Laos, Burma, Cambodia and Vietnam)
So how will AEC benefit Sinkieland?
1. A vast pool of cheap foreign talent (doctors, nurses, teachers, taxi drivers, technicians, engineers, retail executives, bank executives, etc..) of the other Asean countries will make a beeline here.
2. Sinkie GLCs will be able to set up shop without fuss in other Asean countries (this is the main benefit to Pinky and his LEEgime.) Sinkie SMEs may not have the economic clout or the willigness to move their operations to other Asean countries.
Note: If AEC becomes a reality, expect more Sinkie PMETs to be replaced by cheap foreign talent from the other Asean countries. In job recruitment ads, recruiters will not be allowed to employ phrases such as "This position is open to Sinkies and PRs only".
Sinkies should expect more Ah Tiongs and Ah Nehs to live and work in Sinkieland. Ah Tiongs and Ah Nehs have been paying for citizenship in Laos, Vietnam, Burma, etc..The current rate is about 2,000 USD for a Laotian citizenship.