I have a VIA card an never have a problem at all. I have it hooked up to a canopus 100 as well as my camera. I have read many times that they cause problems but I guess I have been lucky.
I hope it comes it at the $200 that I have seen. I am sure there will be music ad-ons that will have to be purchased as well. Long term cost could go up but compared to spending money on packaged music that might be a deal.
I have done this several times. Length of 2 frames seems to be the best (as mentioned). Go to https://www.detonationfilms.com/free_stuff.htm and download the muzzle flash jpgs. You will find what you need there. Just resize and position using composite and you have a perfect muzzle flash. I have downloaded and used several of their special effects. I have also used Particle Illusion for explosions and gun shots.