TBH you can use Chinese unionpay cards to pay things online on Chinese websites just fine, but they are not supported abroad and even if you have debit Visa card it won't work on international websites making it pretty much useless, so for international websites you have to use credit card (pretty much impossible to get for foreigner)

actually online banking ain't that bad, I was doing domestic, forex and international transfers just fine, the login part and verification is the most annoying plus support for modern browsers. i would recommend to use BoC which has own RSA keygen on keychain and requires to install only certificate, CMB worked with SMS verification is you used mobile website but for normal banking you had to install their proprietary app. you rarely have to go to bank if you know what you are doing