As far as everyone knows of the general situation of mixed marriages in Malaysia, I shall take example of the 3 biggest races:

1. Malay + Chinese/Indian = Chinese/Indian must convert to Muslim first.
2. Chinese + Indian = There are cases of converts, and some no need.

Many issues come into play when we're talking about mixed marriages.
One old saying of "when you marry someone, you are also marrying into their family" applies at an even greater degree in this situation since it now involves trying to adapt to new culture, new race/face, and new religion.
Unless of course if that person is already brought up in those environments, then its a different case.

And just like any other marriages; some works, some do not.
I'm not sure if there is a record of all mixed marriages in Malaysia, but I guess everything works out well in the end.

What is your take in this?

The more to mix, the better the gene. Inbreeding cause retardation, out breeding create smarter gene to counter defects and virus, also eradicate genetic disorder if not mistaken.

^
You can preserve only if you marry your own siblings/relatives? 

I don't mind actually.

Yet, no way if i'm converting because of marrying a Muslim. One may argue the point "love the bride, love the bride's religion too".

It doesn't work that way; one needs to embrace the religion in a wholesome package and stay true to its' teachings for the rest of his/her life. If otherwise, why bother?