with lighting for
SW tanks, its about watts per gallon. take the number of total wattage for all light on the tank and divide it by 65g and you will know the amount of light your tank has. As far as the mushroom polyps are concerned, they like lower light( defined as around 3w per g) and may do fine, especially if you already have mushrooms and they are doing well. the little red feathery things sound like feather dusters, which are very common on live rock and a good addition to a tank.
did you use your fathers filter, if so your tank may be close to cycling especially if it was up and running before you got it.
also, do you have a protein
skimmer on your tank, if not i strongly recommed you get one. clean up crew is all appropriate for your tank, and you could get a few more hermit crabs and snails ( astria) if you like, i would consider adding purple up to the water once a week when you do water changes, it will help your boxer shrimp get the
iodine he needs to molt and grow, expect that to happen about once a month and if he looses a claw in the process dont worry as it will grow back the damsel may be buring setting up his territory or is being bullied by the other two damsels. most tanks only have one type of damsel due to their aggressive nature
as far as water changes, i would do a 10% change every 7 to 10 days
hope this helps and let me know if you have any more questions, best of luck
