Congratulation s on running down so many problems at one time. As to both dash turn signal lights coming on with out the emergency flasher on, can mean a little current is flowing thru both bulbs (in series) bypassing the ground. Cleaning the instrument cluster ground might help. To get a current flow, different voltages at the two dash bulbs has to exist. The dash bulbs are paralleled off the front park/turn signal lights, so check the front turn signal lights to have good grounds, clean sockets, and that their bulbs are matched (same part number). My GMC van started doing this a year ago when I installed LED bulbs.