1. Should be OK for Visa & MasterCard only, not OK for Unionpay. But online transaction must be enabled.
2. Card will expire in 2024-2025, Gopayz should be obsolete/discontinued already by then.
3. I checked my ledger, I was still charged and waived of inactive fee in April. But monthly charge of RM2.50 can be waived easily, FYI I used to pay RM1 to my electricity account every month to avoid the monthly inactive fee (discontinued Big Prepaid Card, the predecessor of Bigpay)
4. No cashback.
5. Can use but the transaction will be unsuccessful at the last step. So use other debit or prepaid cards to top up, credit card is not accepted.
6. You can use all 3 cards. All 3 cards will share 1 account (ewallet), no individual credit/balance.
7. Why not? For Shopee and Lazada, only Visa and Mastercard are accepted, most of the online platforms in Malaysia don't accept Unionpay yet.
8. Not sure on reward scheme. But it is a prepaid card, the fee paid by the merchants is very little so the reward to cardholders is negligible, not like credit card which the card issuer can earn a lot from transaction fee and interest charged.

To add on (4), no cash back but occasionally got freebie vouchers.
For Umobile users, seems like there's some hidden freebie vouchers too.

Voucher will be awarded upon completion of certain transaction such as top up or spend.
I didn't use this app/card for a month. Barely can comment much now.

There are 40+ ewallet operators now, but a few of them can survive to become digital bank / financial institution.
Most of the e-wallets will not survive till 2025, eg VCash and Happy MasterCard by Digi is already gone.
Gopayz, Razerpay and B-Infinite are all related to Berjaya Group or Vincent Tan. They are likely merged into 1 entity.

So don't think too far for a technology product. All the e-wallets including Bigpay and Gopayz will go through their product life cycle - development, growth, maturity and decline.

All the ewallet operators shall be regulated by Bank Negara. Your money deposited is safe and will be refunded if the wallet is discontinued.

Boost (owned by Celcom-Axiata and Mitsui Japan) and TNG Digital (owned by CIMB and Alibaba/Alipay China) and GrabPay (owned by Grab and Maybank) are likely to be upgraded to become digital banks, they will offer other financial services such as loan, insurance, wealth management etc in next few years. In 2025-2030, we hardly use banknotes, Cash Deposit Machines and ATMs may become obsolete.

For Lazada and Shopee transactions, you may use Lazada Wallet (owned by Alibaba/Alipay) and ShopeePay for additional rebate.

There are 40+ ewallet operators now, but a few of them can survive to become digital bank / financial institution.
Most of the e-wallets will not survive till 2025, eg VCash and Happy MasterCard by Digi is already gone.
Gopayz, Razerpay and B-Infinite are all related to Berjaya Group or Vincent Tan. They are likely merged into 1 entity.

So don't think too far for a technology product. All the e-wallets including Bigpay and Gopayz will go through their product life cycle - development, growth, maturity and decline.