Would Luno suspend or delist XRP? Some exchanges are already doing that.

It's stated in your wallet.

No, crypto/crypto pair is not enabled.

Price is dictated by buyers and sellers. Different buyers/sellers, different trading pair, different volume. How can you compare pricing between exchanges?

You're not wrong.

How's the trading volume over there? Last time I checked, much much lower compared to Luno.

Yes you can.

There's no one place truly safe to keep your bitcoin. What important is to understand what are the risks and weigh up the pros and cons.

Centralized exchange like Luno is custodial, meaning you give your bitcoin to them for safe keeping, you do not have the private key, your Bitcoins are not truly yours. If they are compromised, they might not able to give back your Bitcoin. This has happened even to the biggest crypto exchange in the world. You are also subjected to the local law and their terms of use. They can prevent access to your Bitcoin if you are "suspected" doing any malicious thing.

The upside is, it's easy to buy and sell, relatively low trading fee and there is a customer support to help you if you are facing problem with your account.

If your base currency is MYR and you are planning to cash out in MYR, I don't see much sense in doing this comparison. The most important thing is your sell price is higher than your buy price to make profit.

Yes, the ETH buying price in Luno is higher relative to MYR/USD exchange rate but remember, it means your selling price is also higher in Luno, which is great. Buying with USD in Binance means you have to consider MYR/USD fluctuations when you want to cash out. If you want to transfer your ETH to Luno to sell, you have to bear the high ETH transfer fee. So all things considered, you might end up having less monies with Binance vis-a-vis Luno when you cash out in MYR. I see merits in using Luno if you don't want to deal with all these things.

But of course, in terms of liquidity, number of coins listed and trading fee, Binance is much better.
Luno has the advantage of local regulation. Nobody knows where Binance HQ is located. But then again, maybe that's not a bad thing

As the saying goes: Tepuk dada, tanya selera.