So, I just finished a screenplay on a very difficult subject. If you want to write screenplays, I recommend several things. First, invest in Final Draft. Final Draft is very expensive but impressive. It automatically formats your writing to industry standards. It also autocompletes everything you want to write such as character names, locations, and standard directions. It also automatically saves every five minutes and will automatically open the last project you were working on. It allows you to click a menu option to register your script, and you can save it in a PDF file.
Final Draft, like any software, makes scriptwriting easy, but it also needs to be learned. It is not idiot proof. If you decide to go in and edit margins or other formatting, you may find yourself in a heap of trouble with a non-standard (read non-sellable) script.
No writer should become too attached to their work. This is especially true with a screenplay. To give my client the best service, I submitted mine to a professional reader. These people are paid to read scripts and give production companies a thumbs up or thumbs down. Paying one to read your script is a great way to get good feedback, but you have to be careful. The difference in price is great. Some are around $60 (I would cringe if anyone charged less than this) and some can cost thousands (again I would cringe at this price but for different reasons.