yah, that does not sound like a good idea! you are messing around with a bunch of things there....the ricotta robbed the whey of its last solids...and who knows what happens at boiling to all the other stuff in there...i sure don't! and then you are adding an unknown quantity of cacl, salt, vinegar....please! you would have to have a complete lab with a bunch of expert chemists to analyze that situation....and they would probably &^%$ it up as well!
salting the feta IN THE BUCKET, to make its own whey/brine is the best......the cheese and resulting salty whey "have made their chemical peace" just from the process alone...they have reached equilibrium by definition........i have never had soft cheese this way.....some not as hard, some a bit creamier, but never swelled.....only had swelled cheese when i played around with other things.....
when you add a bunch of other factors into the equation is when you cause problems......as usual, KISS....cheesemaking is mysterious enough , without adding extra variables.... quoting an old margarine commercial......"its not nice to fool mother nature"....and boy oh boy did that one hit the mark! as in, its not nice FOR YOUR ARTERIES, to fool mother nature!
i can't recommend the gallon bucket/gallon camembert mold method enough.....the cheese slices you pack into the bucket are easy to handle, and open up the cheese for proper salt penetration.....the widget on top to hold the top layer under the brine keeps mold OUT......the cheese is an easy size to cut up later for sale.....vacuum pack, or pack in smaller containers with salty whey.....and, if a bucket goes bad, (usually its a whole batch, obviously, but)...its only a gallon, not a fiver....
one more hint.....take a long knife and slide it next to the salted slices as you pack the bucket.....to allow air so escape from the bottom of the bucket....these slices fit tightly in the bucket...the mold is also the same shape as the bucket, it tapers to the bottom.....so, pack the bottom slice into the bottom of the bucket, with the taper in the correct direction....