Your First Floor
The most basic in terms of changes, the first option has minimal disruption and is kindest on the budget. It also though, offers the least in the way of adding more space (feeling of) and creates limited additional storage in key areas.
In option two we see the creation of more storage (vast in the bedroom), whilst still only making the least amount of changes possible. This means the proportions of the house elsewhere stay the same.
In an effort to loose the dark hallway we have taking that for the master bedroom in option three and created a large wardrobe adding to the rooms square footage making it much better as a master suite.
Now for something different, option four creates a larger master suite with minimal work and creates a small (usable) family bathroom better accessed for the other two bedrooms both of which maybe classed as doubles. If you could block the back bedroom fireplace this would give more usable space in this room to allow for a double bed.
Lastly, the most costly and time consuming project would be option five. This reconfigured the entire floor to create a larger master suite with dressing room/walk in wardrobe and large en-suite plus a larger family bathroom.
There are lots of small changes and tweaks that can be made to all of these depending on your preferences and desires but I hope this gives you lots to think about and helps hone in on what's important to you for your space and your project.
Looking at all the plans together and remembering what you are looking to achieve as well as the fact the kids bedrooms have been decorated and minimising spend, my preference would be for option two with a slight variation (shown right).
For me this gets you all the storage you require for the master bedroom and several other places around the house, loose the dark hallway and is reasonable on cost and time-frames to put in place. The only downside I can see is that it doesn't allow for a bath but this can be achieve by loosing either the walk in shower in the master and replacing with a bath with overhead shower; or loosing the family bathroom storage area and reconfigureing this bathroom.