idle questions

Yes, most likely a vacuum leak around #1 intake runner causing lean condition and white plug. Plugs 2- 5 look ok a bit on rich side, and #6 richer. High float level can be causing a slight rich condition, and an incorrectly adjusted idle circuit can be part of your idle problem.

With #1 running lean, a too low 450 rpm idle rpm, coupled with an incorrectly adjusted accelerator pump will cause stalling during acceleration from idle.

Idle speed can be adjusted by idle mixture screw, base timing, and idle speed adjustment screw. You need to first fix the vacuum leak at #1 (most likely by installing a new manifold gasket), than set idle mixture with the aid of a vacuum gage. Once those two tasks are accomplished, you can experiment with base timing, and idle speed adjustment screw. Chances are you will have to bounce back and forth tweaking idle mixture, timing, and idle speed until it is where it needs to be.

Stock slants like 5 to 10 degrees of advance before top dead center as a base timing.

Once idle speed and mixture is sorted out, and a hesitation or flat spot persists when accelerating, than an accelerator pump adjustment needs to made.