Doesn't sound like you have a problem with the flashing mod..
Answer to the second #1, only need the resistors for the turn signal circuit.

The LEDs have an anode and diode (+ & - if you will). The 1156 and 1157 replacements are indexed just like the original bulbs but the smaller lamps are not.. you may have one or more reversed. I'd put all the bulbs save for the 1156,1157 back in and then one by one put in the LEDs till they are all correct.