1. Use a program to convert the filetype to compress the file, either make it .mpeg or mp4. I'm trying to find a safe program to use for myself. I used to use FreeMake before it's latest update. For 1280x720 (720p) the out file will be anywhere from 15+ GB. But this will ensure HD rendering and will be widescreen. Anything lower then 720p will seem rather unprofessional, or low standard compared to what is common now.
2. Yes it is, but you should read the readme if it comes with one, or the popup box when opening a file as it holds rules. Not all models are editable, and it's highly disrespectful to edit a non-editable model but most people on dA don't seem to care. You will need to use either PMDeditor or PMXeditor, you can get an English download here:
PMDEditor 0139 and 0219 english translation (if you have problems please ask them not me, if you get an error like this then follow my own tutorial:
pmdE pmxE Error Fix). Also if you need some tutorials for what you need I do have a collection for such an occasion here:
razz-pixel.deviantart.com/favo…Also if you try to edit any of my model edits please ask before hand, most of my newest ones are made with my own parts, meaning I made them myself in a 3d modeling program for that character. Such as this character in the deviation, I made it for someone while making almost everything myself.