There is no best way to "buy" BTC directly from exchange as at now, in Malaysia. However, for P2P trading, remitano is the way to go. I may be wrong, but I guess @coingecko @awesomianist will be more qualify to answer your questions.
As for steem, if you do not know, now #esteem app allow user to pay by credit card to purchase #estm points, and those points can be use to exchange with upvotes. In a way, it is still a fairly convenient way to buy Steem. Hope this help.
@crypto.piotr
Sharing my insights.
1) Legal Exchanges
As @davidke20 said, There is no direct way to buy BTC straight from any Malaysian Exchanges. As of now, there are only 3 exchanges that can legally sorta-operate in Malaysia with a Conditional License by the Malaysian Securities Commision. In short, there is (as of time of writing) no legal exchange in Malaysia
2) P2P markets
There's always Remitano, Localbitcoin, Paxful and a handful of other P2P type platforms out there. They are basically Craiglist of crypto so all the cautions are needed when dealing there.... as usual.
3) Private groups
There are also buy/sell groups existing (if you know where to look) that keeps to themselves, you'd have to rely on luck or REALLY knowing the who's who in the malaysian scene to get yourself into a good one. (I am not part of any such groups, only aware of their existence)
Verdict
Overall, if one is looking to buy in small amount one-off, the best way will be looking at P2P markets and choosing the best dealers with proven track record, there will be premiums but they way i see it that is the price of being able to buy without minimal chances of being scammed, it is still non-zero though.