Well I don't wan't you to think I'm saying what you are doing is "no good" or a waste of time. But on the other hand, going, by what you are saying about deads, for instance, I'd have to wonder whether there was a "weak point" to focus on. Unless you mean weak point in regards to weak exercises rather than specific things holding you back in said exercise. Which is really part of my point.
When you are new to really dedicating yourself to something like deads, or squats, or whatever else, if you take the time to really nail down technique and make sure you maintain that technique as you progress (not letting bad habits creep in and cement themselves) then for a while all you need is that.
Now if you had a pre-existing problem like a big postural imbalance or you were very quad dominant as is typical then a qualified trainer would be able to point you to exercises to get the right muscles up and running so that you could perform things like deadlifts safely and get the most out of them. But most beginners are not going to be aware of any of these problems and certainly not how to choose from a list of accessories even if they do need them...which they most likely don't.
You spend all that time doing more complex things like this, adding in more advanced techniques and targeted exercises when you could probably progress more quickly and efficiently by just doing that exercise you neglected but doing it in a reasonable way. Because all the extra stuff...most are going to have a really hard time telling what helped them and what didn't simply because they haven't really had time to discover any weak points that need addressing. It's the same thing with all the squat variations or accessories.
Don't get me wrong..this is a fairly straigthforward and simple thing. I have know way of knowing what you need or don't need. But if, like you said, you spent a lot of time doing just chest then you probably could benefit from a simple program focusing on the big three and adding in other things as needed or appropriate. Perhaps focusing on overhead press along with squat and deads for while and just doing enough bench for maintenance.