I am very intrigued by all these instances of account suspensions. Seems like we hear about a story like this once every few weeks.

Based on the black and white parameters set forth, below all seem like legitimate actions:
- Converting HSBC RewardCash to Asia Miles with names matching on both accounts
- Converting Amex points to Asia Miles with names matching on both accounts
- Adding/Removing any individual of your choice to your redemption nominee list, even with different surname.

Not sure why the first two course of actions would raise suspicion in the eyes of CX?

I can understand how changing your list often and redeeming for your newly nominated companions a lot will raise suspicion; but as far as I know CX hasn't prescribed a limit on the frequency you can change your redemption nominee list. It still shouldn't be grounds for a suspension.