Do you mean keeping the ballast wires and circuits ( blue and brown, RUN and START ) like stock without fuse ?

Yes you can do it, is not a bad idea... never though on that because I was making the setup with the Painless fusebox option to "coil"

how many amps ? 5 max. Original fuse for dimmer source is 5 as far I remember on my Charger. It should be casted on your original fusebox and stated on car's owners manual. Maybe A bodies are smaller due they use to use less bulbs to dash.

Remember if you still wire the dash instrument like the point #11, gauges ( and warning lights ) will still turned off when cranking. It is originally wired in to the RUN ( blue ) circuit, and now is being souced by ACC by painless, what doens't get the feedback power spliced from cranking circuit at ballast