Either of these things will make the models appear white.
If you downloaded a file without you computer being set in Japanese sometimes the texture files will turn gibberish and won't be the same name as they are on the model so they won't show up. If you have PMD Editor you can open up the model and check the texture file names, if they're different you can manually change them but it's usually easier to just re-download the model with your computer set in Japanese.
Alternatively if they aren't in the same folder they won't work either.
Hope I could help~ ^w^
Since I'm still a newbie on this, to convert it to an avi file..You go to File and go to "render to AVI file". (You need to put a name for it.) Then you have to put the range of frames you want. (For example, Frames 0 to 20). After that, it records all the frames.
(WARNING: it`s Japanese, and you have to guess. I heard it won`t run without Japanese locale in your computer)
Move? click arm on the side, fin the rotate button, and move.
You can either select the "Center" bone, then click "box select" and click and drag a box around the entire model and then select "Move". Then you should be able to move your model around the screen ^w^
Another way *depending on the model your using* is to select the bone between the models feet *sometimes called a "Master Bone"* and click move and the whole model will move with it.
Hope this helped ^ u ^
To move the model without the buttons in the corner simply select the bone you want to move and in 'Bone Manipulation' box select either 'rotate' or 'move'. A control will appear over the bone you selected and you just click on the different coloured lines to move the bone.
Camera movements with a mouse:
Left click(hold): Will rotate the camera
Centre scroll button(scroll): will zoom in.
Centre scroll button(click and hold): will move the position of the camera around the screen.
Hope this helped ^w^