HiYou have to download some software for it, for example i use VideoCharge Studio. (it no free soft, but has free-trial)nextYou can review your video and remove some bad scene. (It you can reduce file size)http://www.videocharge.com/Index.php have to set video setting (bitrate) so that reduce size. http://www.videocharge.com/Index.php. It is very easy.
I agree - remove watermark impossible. But for some video you can hide watermark very effective. As i wrote below there are there ways for it: crop, blur and use nearest pixels. Of course, if you have big watermark - you cannot remove, but on 90% video have small watermark which you can remove!
HiReally, I download VideoCharge Studio and i can:1. Add watermark on video (text, image or small video clip)2. Remove watermark from video. (use crop, blur or use nearest pixels)Very very good! Recommend to try!