With our kits, you can install the sights before draw filing, but just be sure to remove them when you do the actual filing.
Everybody has their preference when it comes to these sorts of tasks, but I prefer to use an 8" mill file when draw filing. I choke up on it, holding it relatively close to the sides of the barrel. This seems to give me most control and allows me to work fastest. I push when draw filing and often move the file slightly left or right with each subsequent stroke to spread the cuts over the file. This maximizes the working time between when the file needs cleaned. With a good file, I find that a simple tap usually knocks out the cuttings. I also don't find pining to be a problem with a good file and have never been fond of chalk. My choice when draw filing are Bacho files. They just seem to be a step above the rest, but are a bit more difficult to find.
Hope this helps. I plan on starting to do a series of videos this Summer and this would be a great topic for one.
All the best,
Jim