This seems to be a noobish question, coz i nvr used editor programs...but well~

Is there any way you can change a main chr's race after chr creation?
Also, any ways to change alignment? chr portrait? etc...

THANKS~

A program called GateKeeper lets you change various characteristics such as attributes, alignment, class, inventory, proficiency points. Having said that, I should warn you that mucking around with your character's file can be a slippery slope that leads from tweaking to cheating (an extra dexterity point here, a few wands there, etc.). If you still have fun with it, then go for it. That's not for anyone else to decide. The other aspect of using GateKeeper is that you might inadvertantly crash your game if you change around some of the global variables, so experiment with this wisely.

Plus it's never completely safe to edit your game files. Abusing GateKeeper will probably make BG1 boring...use it wisely ;)

Your portrait could be changed through the customize button on the Record page.