If the Pip-Boy were to be improved, the game's story would probably have to be revised to reflect that and explain that.
So we need to be careful not to violate the game world's reality. The Pip-Boy is made by the Robco company, a place that we actually visited in FO3, and whose founder we met in FO:NV. Since FO4 is set only a few years after FO3, their Pip-Boy should look similar, as they do now. But your numerous additions would make Pip-Boy look like a major upgrade.
