Whats happening to my plants? (azalea, acer, fern)

My Azalea has been sufeering some "spots" on it's leaves and the odd yellow leaf. It has been neglected for a few years and I've only recently started paying attention to it with Azalea liquid food feeding (once every 2 weeks) and a round of seedpod dead-heading last month:



Some of my ferns have suffered discolouration on the leaves:


And my Japanese Acer, all of a sudden it suffered massive "leaf scorch". I noticed the bark near the roots have been scraped off (maybe by an animal). My research says that "a change in environmental conditions" may case this. I had been using lawn weedkiller (for dandelions) and other chemicals on the surrounding lawn which might have affected it. It was pretty sudden. I watered it every day but not letting it get water logged:




Thanks!

 

Hi Loofah,

Tap water from outside tap. Should I try the Azalea food for the ferns, acer and other acid-loving plants?

The Acer actually has some nice leaves near the base (below the stripped bark area). It's just everything above it that is scorched. I think I may have overwatered it.