So I brewed my Mr. beer WCPA and it went smoothly. I put it up in my kitchen cabinet for fermentation on January 31.

The first 12 hours I had a good amount of fermentation. I had it in there For 3 days, but we were running unnormally high temps here in Texas and it got to be about 78 degrees in the cabinet. So I decided to put it in a mini fridge, but the temp went all the way to 56 over night. I took it out and put it back in the cabinet for 4 days and the temp here finally got colder and the cabinet is about 70 degrees now for last 3 days.

My question is - I noticed the first day there was a little bit of fermentation on the top, but I saw it dissapear once i moved it back to the cabinet from the mini fridge 3 days ago. Have I royally screwed up this batch? Should I do anything to encourage the fermentation on top? Add more yeast etc...

moving it from warm temps (which the yeast likes) to colder temps will slow down the yeast and can possibly make them stop fermenting. with that said, fermentation can take place without many visible sings. the only way to know for sure that the yeast stopped is with a hydrometer.

Things usually slow down after a couple of days anyway. See if it tastes like flat beer when you hit 2 weeks. If it still tastes sweet, give it an extra week.

Most ales need to ferment below 70* and yours probably got over
80* inside the fermenter due to the fermentation heat and that's
bad news for beer. Fussels, bubble gum, banana and other bad
esters may be in there. At bottling I would probably just use
4 ea 2 liter sprite or mountain dew bottles so you are not tying
up your normal bottles. That way if it's not drinkable you can
dump it or try to age it out.

pull a shot glass sample and get back to us with what it tastes like.
since the temperatures are nice now, if you GENTLY rock the keg to stir up the yeast (after you pull the sample liquid of course), that would help get some back in suspension and, in turn, back to work. another week to 10 days of fermentation would do nothing but help at this point as well!

Hopefully you pitched cool and your temperatures stayed below 70° for the beginning of fermentation. Many of the flavors are determined at the early stages of fermentation.