That's all good ideas. BTW, what about chinups/pullups? Can you do those?
I wouldn't put too much thought into bicep curls.
The only thing that I would point out it that you CAN do 50 pounds. You can count reps and get caught up in intensity cycling which is what resetting the weight is.
But a simpler thing to do since you say you can already do 5 reps is to basically find ways to increase volume by different means.
For instance you can progressively increase density. Since you can do 5 reps (for one sets) you could try 50 pounds with say, 3 reps at a time.
Rest enough to maybe allow yourself to do two more sets with 3 reps.
Then the strategy is to do that same amount in less time. So decreasing the rest periods. As the rest periods get shorter you should find you can do more reps in one set.
Or, you may find benefit from stepping up the weights. So, say starting at maybe 30 for a set, going to 40, and then to 50. And then next time you try to increase the reps on all the sets. Or add a set. Or add weight to one or more of the sets. Or anything you can imagine
There are many ways to progress and this can be applied to all sorts of exericises.