Modeling and Realflow development

Recently I tried to build liquid with Realflow to fill my model but there were several issues came out:

1, The liquid didn't act naturally as I expect. They crowded each other especially when more and more particles being simulated.

2, The liquid can't fill up the whole model. Particles can't come into the left arm.

3, There are alway some particles jump outside the model even though I used the "Kill volume daemon"

4, The mesh is larger than my model.

Besides, I start to model and I found it is hard to rig my model because it don't have enough geometry for bending or twisting. So I may ask for some help with the modeling and rigging.