Yes warm up. Cat 5 races are going to start hard. They might not be efficient in the middle. But someone will light up an attack and you’ll have to do a hard effort to stay in the pack.
If you have a very small saddle bag then perhaps use it. Otherwise just put the tube and CO2 in your pocket.
You should bring the minimum supplies needed to get you back to your car if you have a minor, but significant mechanical problem.
If you get a flat your done, and odds are the sag wagons going to just pass you by.
To clarify… in a crit, there should be no saddle bags, pumps, lights, or anything that could easily become unattached. I think on the track they technically don’t even like head units unless they’re attached by a tether as well as the quarter-lock system. For a RR, typically it doesn’t matter. The reasoning is because in a crit, you’re usually at much higher speeds and typically much closer proximity. That’s why the EB mentors had you lose the saddlebag. It’s a pretty common thing to see ditched saddlebags etc. on the side of the start/finish area of the EBs. I would NOT put CO2 in my back pocket (or a pump) because if I crash, that’s going to cause nasty problems to my back. At the Lodi crit this year two gals crashed, and one of them kept rubbing her back later because she obviously had something in her back pocket that had dug into her back.
For CRITS, no need to have any sort of tube, CO2, etc.–spare wheels in the pit, and that’s it. For a RR, that’s a different matter.
Warm up a little. Too often people do super elaborate warmups that they perhaps aren’t fit enough for an tire themselves out. So, roll around a little before the race and then use the first few miles to spin out your legs and get warm.
Use a saddle bag/flat kit. You’re likely right, if you flat you’re on your own so be prepared. If/when you get more into it and/or move up in categories you can have spare wheels in the follow car (if there is one).
Always spin your legs in as light a gear possible. Save your legs for when you really need them. When you watch the Tour de France, or any big race, when the pack is just rolling along their cadence is quite high. This is due in part to the speed, and in part due to the fact that the guys are keeping a light touch on the pedals.
The answer depends. I coast a lot and move in and out of the wind to slow down so I don’t brake as much. I am comfortable at a high cadence (105+), so I tend to spin faster and coast. I like that being in a relatively easy gear lets me spin up faster for responses or attacks as well, instead of mashing at a lower cadence every time I need to respond to something. That’s what works for me. If you’re comfortable spinning quickly, it’s what I would recommend to preserve your legs a bit better over the course of the race.
Experiment. That’s something you need to figure out yourself. Also, draft as much as you can — be smart and lazy. Close small gaps immediately by putting in one or two strong pedal strokes, that’s often all it takes.
I like to produce force at lower cadences, so I usually prefer to keep my cadence low. However, my average cadence during races has been consistently higher than during normal outdoor rides (about 90 rpm vs. 80 rpm).