1. I went with full bearings. I wanted to do bushings but I had bearings on hand so that's what I used.
2. As for fps, I got it around 300-310. I cannot remember the full auto setting because I chronoed it at the field right before a match. I haven't fired it since earlier this year (thanks college) but it was around there. I built it for close quarters.
3. Hop up is very basic. It's just whatever came in the gun. Its not great but I am making shot from 10 feet away most of the time so it doesn't really affect me. That said, it begs for a nice hop and barrel setup. I just never got around to those upgrades.
4. I have never had a problem with the drum feeding. There have been some times when it has needed a little shake but usually that is when the battery is low. It is powered by a standard 9 volt built into the drum. It does need to be swapped out every now and then so it is not a bad idea to keep a spare in your bag.
It definitely wants someone to give it some more parts to complete it. But my project with this gun was to get it working again without Classic Army's help (or lack thereof). It feeds every round. One thing I did forget to mention was that it has a Super Core POM piston installed. All the other compression parts are stock. Last I checked, the compression was good. I honestly did not expect this project to work so that's why it doesn't contain top of the line parts. Most of the extra money from this gun comes from the drum, the Tienly, and the Perun, which is over 200 dollars in extra stuff as it is. I am willing to come down on price and the real only reason it is at 450 is to compensate for shipping. If you want to make an offer or negotiate, feel free to shoot me a dm! I'll give ya any answer you want.