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'm planning something similar, so I'll throw out some ideas to get you started. I'd do a 6 ft wide closet with a sliding door and a 4 ft wide bathroom. That will leave you 1 ft of wall space down the center for the plumbing and you can make that smaller if allowable by code and give the extra space to whichever one you'd like. Put the shower along the back wall (kitchen wall), then toilet and vanity. You should be able to fit a 26-ish inch wide shower along the back wall and a 31 inch vanity, depending on code. I say this because our hall bath is 4 ft 9 in by 11 ft, but we have a closet that bumps into the space right around the 7 ft mark, so our bathroom space would be somewhat similar. Obviously, your code might be different, but this might give you something to kick around.

The "regular" bath layout that jensbride posted first is very similar to what our DD & DS shared for years and worked very well. The door, however, was a pocket style and placed directly across from the toilet. This allowed the vanity to be scooted around the corner to take up the whole wall. It leaves the toilet close to the tub, but with lots of elbow room. Our kids just learned to keep the door partially closed when the bath wasn't in use due to the "view".

My question to you is: how much do you like your knees? Love this little conundrum. Reminds me of so many awkward little bathrooms that were made at the turn of the century or earlier, Now I'm not a designer or anything and this is with MS Paint (10 pixels = 1 inch so it should be vaguely to scale I hope) so take this with a grain of salt but: I did move your window but if you don't want to move it you can just flip the position of the toilet/sink (though I believe Door 1 is the kitchen door so I left the toilet closer to the wall bc then it'll be kinda out of view if the door is slightly closed I hope?). Not sure if this would work bc I don't have the dimensions from wall to door trim on Door 2 and I'm assuming its the same size as Door 1 this one moved the window again but kept the same layout you have now. I just sized the fixtures to fit the room; same toilet but adding a shorter than average 30" x 54" 2-sided tub (you could probably get away with 60" length though) and a smaller 18" x 30" sink (and I'd suggest going even smaller with the sink tbh, shallow sinks might help in this bathroom) I went a bit crazy for number 3, no structural changes but a lot of plumbing moves! In this one I would suggest a corner sink if thats still a thing or a shallow sink if you're open to it, they're great space savers! The layout you have now is probably the most efficient one you could have in there with the location of doors and size of the room, unfortunately. My ideas at most have about 19" of walking space between the tightest fixtures granted thats all hip height and below obstructions so it might feel more spacious when walking. I've found with the tiniest bathrooms over the years that vertical obstruction height is the real killer since your arms typically take up a lot more space than your feet! Honestly I'm not sure if this is your main/only bathroom (I think so since you want a tub in a space you know is too small for one) and I'm not sure what things you'd prioritize over others (storage, view, movement, basement access, etc.) or if the non-door/window wall can be bumped out a bit, even partially (I assume not since bumping out that wall is an obvious way to get everything you want) Also on the point of barn/pocket doors: do NOT do it unless you have the money to spring for a top tier one and even then I wouldn't suggest it. Yes, they are space savers but honestly they come with a host of issues (getting stuck (pocket), coming off the track (pocket & barn), cleanliness (pocket), etc) and even then they wouldn't address the issues you have with this bathroom What you really need is to close off or move those doors, even moving the full bathroom to a different room entirely, which unfortunately is not possible. Changing the opening style won't give you more room to put the fixtures you want in there unless you want to crawl/shimmy/sidestep past your toilet/sink which I don't think would be up to code! If after all my rambling you're not into that might I suggest taking a gander at the old Sears (and equivalent) home plan catalogues? They have so many tiny and rather confusingly laid out bathrooms like yours so you might have a moment of inspiration! http://www.searsarchives.com/homes/1908-1914.htm (granted some plans don't show the layout of bathroom fixtures but there are some that do like The Chelsea)