You are going to want more than 32" for the toilet. 36" is standard (and perhaps even code in some areas???? Not here in Maine but I heard people saying that on other forums...) We have 34" and it feels fine but I dont think I'd want to go much tighter. You could solve that simply by flipping the closet and shower. So, have your shower -rotated 90 degrees and witha glass end wall- at the end of the tub (which is a nice setup you can see in many bathrooms, the tub deck can actually protrude under the shower glass wall and be a ledge or seat in the shower). Then the passageway moves to the left, and you can steal a bit of space from the other closet for the toilet. Either that of have a shorter vanity. 48" isn't a size I'd fight for. It's too short for a double vanity, really (unless you're using one of the new two-faucet 'trough" styles) so why not go down to 42" and have a better toilet area? For resale, though, you should consider a double vanity. Some people I guess expert truly huge ones, like at least 5+' long. But you CAN get smaller ones, Ikea has some great ones for tight spaces. But if you're not selling anytime soon, do what YOU like!! (But I still think you'll want more toilet space...)

4'x7' is a waste of space when it comes to a closet. It's not big enough for hanging except on one wall and a bit of the small wall. You'll get better storage in less space with a simple reach in closet with organizers. The bath itself also needs to increase in size if you want a soaker tub and a shower. A soaker tub isn't designed to work with a shower. You need a shallower tub with an integral tile flange to work with a tub/shower situation. A deep soaker tub will be a PIA to step into to use as a shower, and you'll have water infiltration issues if you try to use it as a shower as well. Also, most 4 bedroom houses would want to have 3 bathrooms. You may want to rethink your wants and needs and the small size of the space you are working with. One needs to reduce, or the other needs to enlarge. Since you say the budget is small, and this will be an expensive project, I'd suggest reducing some of your wants, and eliminating one of the bedrooms to better utilize the existing space split between the others. A 3/2 is a common configuration, and would give you more space to work with for the design. Remodels like this are costly because of working within the constraints of the old footprint and accessing the major systems. Also, integrating the old and new isn't always successful. It's just easier to do plumbing and electrical and HVAC (all of the expensive stuff) when the walls are completely open and you don't have to fight the old stuff into submission. It's one of the reasons teardowns of older homes in older neighborhoods became popular. It's less money, and you end up with more house that has more modern proportions and amenities.

I'd like to see the vanity across from the toilet. That way people using the toilet can immediately wash their hands. If you need to split it in two for multiple person simultaneous use move the shower separate. That would also give you the possibility of a bigger shower. And yes, a pocket door to separate the two spaces. It's all going to feel very tight and small. This is almost what I removed during my remodel of my master bath to make one large room. You're blocking off any light from the window near the toilet to the other space. When I took those walls down the light now floods the entire bathroom and is a huge improvement.

What type of window do you have now? Have you thought about converting the window to a transom window above the where the shower / tub would be? That way you could still get a lot of natural light from the window but it would not be in the actual line of the tub.