You mean just suspend as in 'sleep'? Like closing the lid on a macbook. I am doing that with the regular framework 13 (same amd though) multiple times a day.
Still depends on your threat model. Not everyone lives in a place where stick-ups and random arrests are so common place that you want to inconvenience yourself 99.999% of the happy flow.
Re: the bank apps: that really depends on the bank and the country. I live in a eu-west country and there are afaik no apps that do not run on Graphene (which did suprise me I must admit).
Whatsapp can work if you use sandboxed Google Play (I still use a Google account, I just don't want gplay to have effectively root on my device).