Online video editing? [on hold]

I want to develop a Website in which user can type a word and sentence. For each word one video file is stored on the Server. When user type a word then correspond video will be shown to him. If user types a sentence then for each word correspond video should be appended and shown to the user. For the sentence, before appending the video, initial and last 5 second video should be cut and then middle part of the video should be appended and shown to the user. For developing the mentioned website I am having following queries? 1.) Which Language should I use e.g. PHP, Python etc.? 2.) Should video be stored in the Database or path of the video should be stored in the database? 3.) For displaying the video for the sentence, what could be the best way to implement? Thanks in Advance