IMO you will probably not have the time to be able to go back to your room first as there is no direct bus from the Dolphin to FW, or at the very least be so rushed and possibly stressed you wipe out the reason for freshening up in the first place. You would end up having to take a bus to the Dolphin, getting up to your room to freshen up, then have to head to Hollywood Studios from your room to catch a bus to FW then as mentioned before an internal bus down to the settlement. Can it be done? Most likely if you hit the busses right. Have to wait 10-15 for 2 of the busses and it's probably rush time and maybe a missed ADR.
You should have plenty of time to see that Nemo show and make the 2nd (615p) HDDR at FW. According to the web site the Nemo show is 40min, give yourself 20 to get out of the show and walk to the bus stop that's now 4p. Take the Bus to FW and you should be there easily by 430p if memory serves if you don't have to wait too long for a bus. Think I have also had that bus from AK to FW stop at Blizzard Beach, but it still gives you plenty of time. You can then relax a little at FW and check out the stuff around the Settlement before the show.