Start with better ammo before investing in sighting systems; master the AK as it is before attempting to reinvent it.
This is your best bet.
Learning its manual of arms, and becoming comfortable and experienced with the rifle, will make 99% of all other complaints go away.
Most shooters aren't up to doing that with the stock sights however. AK sights aren't made for precision accuracy and very few American shooters know how to shoot well with iron sights.
I tend to agree, and that goes for all types of iron sights too. Shooting realistically from field positions is another problem, but also a whole other story.
I do find it interesting that the AK's iron sights are the same as most hunting rifles that still have them (and actually better than many), and the same as "most" military iron sights, yet they are somehow inferior. Yes, they may have a slightly shorter sight radius, but I have current commercial rifles with a similar sight radius, and I rarely hear anybody complaining about them.
If you dont take the time and effort to learn to shoot properly, it doesnt matter what you have on the gun, or even what kind of gun you have, your results wont be all that good.
All scopes do is let you see the target better. They dont make the gun shoot better, and in many cases, the scopes and their mounts can cause more aggravation than the gun itself.
Red dots are not scopes. They are sort of an in between type sighting device. They simply take the alignment issue of the iron sights out of the equation and focus it onto one dot. Where they really shine is, they are very fast to use, and enhance the guns use in a more realistic manner. They usually do not provide results that are better than the iron sights, if you can shoot iron sights, as they usually offer a less precise aiming point.
Adding peep or aperture sights to an AK may or may not help you. Personally, I dont think they are necessary, and in some cases, I think they just aggravate things.
The Mojo type put the peep way to far forward to be used as a true peep. The couple of the rear mounted type I've seen, put them, or parts of how they attach to the gun to close to your face, which forces you to not mount or hold the rifle properly. You need to have your head down and forward to properly do so, with your nose at or alongside the rear of the top cover, which these type sights tend to interfere with.
If you look at the "real" AK variants that have peep sights, they are mounted more forward on top of the cover. These are not some aftermarket thing either, but factory engineered and issued sights and do work. I believe Krebs has something similar, but no one else seems to want make the effort to take on the top cover.
If you want to add a red dot to the AK, you have to make some serious decisions, and you may end up spending more than you paid for the rifle if you want something that works without making concessions.
If you go cheap on the dot sight, its probably not going to last very long under moderate use. By cheap, I mean anything that isnt a mil spec type sight. In the long run, you'll end up spending more on the cheap sights that you will buying the better ones outright.
The mounts are another issue, and everyone seems to have their favorite. The best I've found so far, has been the Ultimak rail that replaces the upper hand guard. Its well made and engineered, rock solid, and proven. It sits the lowest of any of the other mounts available, and allows you to cowitness your iron sights through the tube of the dot sight with the right dot/mount set up. The rifle shoulders and shoots just like it does with the iron sights, and you have the same cheek weld. This set up puts the dot low and out front, out of the way of your field of view, and out of the way of handling the gun. You also dont have to remove it to clean the gun.
Most all the other rail or red dot type mounts position your head to high and to far rearwards to allow you to shoot the rifle naturally.
Your going to have to decide what you want the rifle for, and what you can afford or are willing to spend if you want to go this route.
Trigger wise, the best triggers are the original factory triggers(I dont mean the crappy US replacement parts). Next to them, the best I've found are the Red Star Arms. I have one of the Tapco G2 triggers in one of my guns, but its coming back out, as its worse than the Century trigger it replaced. I know a lot of people rave about the G2, and I probably just got a bad one, but if I decide to do it again, it will be another RSA trigger.
Other than slap, I've never understood the complaints about the AK's trigger. Everyone I've shot, even the ones with slap, have been better than any of the stock AR/M16 triggers I've ever shot, and of all the AK's and AR's I have or have had, only one AR has had a nicer trigger, and thats because its a tuned match type trigger.