Okay, starting with the roots- they don't look they are in
horrible shape, but they definitely do not look happy to me. First thing that I would do is use a kitchen sink faucet to have lukewarm water splash over the roots before you repot your phal into the clear pot to get the rest of the soil off. It is really important to make sure that the roots can breathe because they are the majority of what the entire plant is using to breathe- phalaenopsis are epiphytes= "air growers" they don't like soil or dense peat at all because it will suffocate them.
After getting all of the soil off, I would go through the roots and see with ones are exceptionally soft and mushy and cut them out with a sterile utensil (don't want to introduce bacteria/viruses to an already stressed plant). After I cut roots, I dab the cut ends (the ones still attached to the rest of the plant) with a little bit of cinnamon (regular baking or cooking cinnamon works) to work as a natural antifungal. Then after trimming the roots- pot it in the smallest clear plastic -preferably UV treated plastic or polypropylene (recycling code #5 is usually printed on the bottom of these) pot that you can fit the roots into.
Pack the bark in fairly tightly to make sure that your phal isn't "wiggly"- it should be pretty firm in its positioning. If you are going to use a new set of bark, soak it in water and rooting hormone for about 24 hours to help get your phal going in the right direction- it will help it produce more roots that are acclimated to the bark. BUT follow the rooting hormone directions VERY CAREFULLY- too much can spell disaster
What I recommend in regards to watering/overall care of your phal is to check it everyday- which DOES NOT mean "change something every day"! But rather, check the bark to see how fast it is drying out since the last watering, check the leaves to see if there is any improvement (because hopefully it won't get any worse), and when there is a spike/blooms, check to see how they are growing, etc.
I would also recommend that you grow your phal either on top of a humidifier tray (can be gotten from nursery supplies) or, as I do, grow my phals on a small plate or bowl that has river stones in it and about 1/4" of water to help provide humidity. When watering, take notice of approximately how heavy the phal (pot and all) feels in your hands and eventually, you will be able to start to get a feel for when the pot starts to feel "lighter", which will signal that it is getting close to watering time again.
I think that would be a good start... Definitely keep us updated and we will help however we can! Good Luck!