Lots of good engineering and design choices to me. I’m going to go in order of the photos you posted. Many of the suggestions are quite minor, so choose what you want to do with your time crunch. unless, im counting wrong, i believe there’s 9
photo 1: It’s risky to have your intake rollers unsupported on the bottom during competition. Screws get loose often. However, I see why you have them like that and it’s benefits for grabbing. I suggest attaching lockplates in place of, or in addition to the collar and connect them to the sprocket. Also, is it possible to squeeze the sides of the drivetrain closer together? I can’t tell completely from the photo, but it looks like the robot’s axles are longer than it needs to be
photo 2: I like what you did with offsetting your top roller with your bottom roller. The chaining for that seems fair enough. I can’t tell whether you’ll need larger sprockets or not though. However, I see that the motors are also chained to your main intake. Because of this, you’ll have power decay. I suggest hard mounting your motors to improve your bucky intake, but using a set of gears or chain to continue to power the large ball intake. You can probably install the gearing between the mounting bar and intake roller and use the axles to your advantage to defend the motor
photo 3: I noticed you have a lot of motor power going on that lift system. 4 motors at 3:1 should give you about 72 pounds of lifting force. You can probably take away 2 motors and use them on your drivetrain. In reaction to this though, I also noticed that you didn’t use rubberbands. They’re cheap, you can find them in common stores, and they give you free power.
photo 4: I think you should place a cross bar across the front of the robot near the front. It should significantly increase your stability and your tolerance against defense.
photo 5: At a competition I went to, I got called out for having a rollguard like that. We were forced to remove it due to “intentional damage”. Plus they weren’t stable enough anyways. I would replace those standoffs for actual channel.
photo 6: More picky stuff. your motors are currently exposed to ramming and the electronics aren’t tied down to metal. A robot has the possibility of tearing out your wires.Zipties ftw.
photo 7: the front of your intake looks connected by only 2 standoffs from the intake to the lift. Try your best to increase it to 4 points of connection
Photo 8: Your scissor lift has a lot of screw heads facing inwards. That will slow down your maintenance during competition. By having screw heads out, your team can easily tighten bolts without getting in each others way. Also, if you move your batteries and/or your scissor lift forward, i think your gravity will be more centered, allowing you to turn quickly. Also, you should add a center wheel, or change your wheels to high traction. Right now, its extremely easy to play defense on your robot from the sides
Photo 9: Did you consider sinking into the foam tiles when making your elevated drivetrain? we had an orientation like that, but we forgot to consider sinking.
EDIT: I haven’t watched the videos, I wrote this in school
my advise is as soon as possible get aluminum bars on instead of steel then you can lift faster and still hang 
