It is ok to do some more partial draining if you want, or you can leave the CYA at 80 and just run a little higher than normal chlorine levels and you would be fine. (Take a look at the Best Guess Chlorine Chart in my signature below for more about that.) An upside to running a pool with CYA a little on the high side is that you can usually get away with adding bleach a little less often.

You may want to work on lowering the TA and pH. Go to www.poolsolutions.com and click on 'guides' on the left-hand side. There is a guide for how to lower alk. But, please read the link in my signature about using muriatic acid safely before doing so.

Hope this helps! (Hope your foot heals quickly.)