Practically every employer claims that every terminated employee was fired for insubordination (not following a reasonable rule). EDD increases the employer's unemployment contribution percentage where an employee is fired without a valid reason, so it's entirely natural for the employer to connflate the facts to defeat the employee's claim.
So, the first part of the answer is, "yes," you should appeal, because you have absolutely nothing to lose by doing so.
Failure to meet a sales quota is not grounds to deny unemployment, as long as the employee has done his or her best to perform. And, since that is mostly a subjective issue, the employee's testimony will generally be believed as to whether or not he or she did his best. So, you can throw those two issues off the table.
If you missed a meeting about which you had no notice, then you can't be sanctioned for that reason (assuming that the administrative law judge (ALJ) believes your testimony. Similarly, if you were suffering from a virulent flu, and your physician will give you a note concerning this issue, then you can hardly be found to have been insubordinate, given that even if you had called, you would not have been able to attend the meeting without putting other employees at risk of becoming ill.
This leaves the "misconduct" writeups. If those had nothing to do with attendance, then they aren't relevant, because the employer has already stated that they weren't the reason for your termination. However, you can probably expect that the employer will change its story at the appeal hearing, so that's a risk, unless you have a good reason for your misconduct. Though, if there is a great deal of time between the misconduct and the termination, then you could argue just that: the employer is changing its story, because if the prior misconduct claims were relevant to the termination, you would have been terminated long before now.
In short, you need a credible explanation for every one of the potential claims against you. You also need to try to get a copy of your personnel file, because you may discover that the various "writeups" aren't actually in the file -- which could make the employer appear to be lying about everything.
You have a legal right to inspect your personnel file
, and to make a copy. The employer may decide to let you inspect but refuse you any equipment with which to make a copy. So, bring a phone with a camera, or better than that, a handheld scanner and a personal computer, so you can make your own copies. Then, if you think that there are records missing from the file, you can ask the ALJ to order all of your personnel records produced at the hearing, and if those writup records are missing, then you're golden. And, if the records suddenly appear, then you can show your copies and claim that the employer has concealed/spoiled evidence (which is a crime).
The point is you need to be prepared to try to explain away each of the employer's complaints as "de minimis" (trivial) -- which simultaneously trying to find a way to show that the employer is blatently lying about some part of its claim. If you can do this, then you will win.
Regardless, unless you appeal, you'll never know whether or not you could have obtained benefits.
Hope this helps.