The sequence you have figured out seems right to me. I would apply the Sylglide as follows:

1. To the gasket where the distributor cap seals.
2. inside the rubber boots where the wires connect to the distributor cap.
3. Inside the rubber boots at the spark plugs. Sometimes I install the plug, then grease the connector end and the white porcelain part, the push on the wire and boot.

You don't need a lot of grease on the boots.

I don't know if you are replacing the ignition coil but all rubber boots and electrical connectors at the coil should be opened and the silicone grease applied. On the connectors, I fill the female part with the grease so that the male part pushes the grease out when the connection is made. This effectively fills all voids and seals out air and moisture.

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1986 300E
1993 Volvo 940 Wagon
1984 Volvo 240 (daughter's)
1976 Dodge 1/2T pickup, gas hog