Calculate the amp draw on the LEDs you plan to use. Most LEDs have a draw of 20mA. I say most because you can get some that draw as little as 2mA. But let's assume that you'll go with the average 20mA LED.
Starting at the top bar, you have three rows of 11 LEDs. IF you light all of them up, that's 33 x 20mA = 660mA
The fletchings are two matrices of 3x9 LEDs. Again, IF you light them all up, that's 27 x 20mA = 540mA - both sides that's 1080mA.
The shaft is a comprised of two rows of 15 LEDs. All on, that's 30 x 20mA = 600mA
Plus one LED at the tip, that's another 20mA.
Put them all together and you have: 660 + 1080 + 600 + 20 = 2300mA = 2.3Amps just for all of the LEDs to be on all at once. Now, keep in mind that these calculations are based on all the LEDs being on at the same time at full 100% duty cycle. Based on your description, they won't all be on at the same time, so the total draw will be lower and dependent on how many are on. However, it's always a good idea to figure out what the max draw could be.
On top of that 2.3A, you need to add the draw of the various sensors and micro controller. For the sensors, read their specific datasheets. It'll tell you their max draw.
A standard AA battery can provide somewhere between 1.8 to 2.2Ah, so if you have four of them in series (for 6V), you can drive all of those LEDs together for just under one hour. Again, [u]if they're all on at the same time at full 100% duty cycle.[/u] You could also get a LiPo battery and drive them that way.
So, answering your question of whether this is feasible? Sure. However, will it be light enough to wear as a sash so it doesn't sag out of shape, that remains to be seen. What kind of LEDs were you thinking of using? What kind of sensors, and how heavy are they? What material is the sash made of, obviously a silk sash won't hold its shape. You need to think of how the shash will change once you start adding all the wires needed to drive those LEDs. Likely also several shift registers to drive that many LEDs. Or you can look for LED strips. What are the dimensions on the sash anyway??
It may be worth looking into getting some custom boards made, the top one containing the three sensors in one board and the bottom one containing the remaining sensors and a micro controller (instead of using a Flora.)
I've done several wearable projects with custom made boards and LEDs. It's easier than you think, once you figure out your limitations.