As you get used to it, you will find yourself adapting to this built-in rhythm. You can shoot them when they aren't pulsing or spin out of the way. Watch out for pulsar tankers at higher levels that split into two pulsars on either side of the tanker lane. Regular tankers contain two flippers. Feel free to shoot them and their cargo with impunity.
Fuseball tankers are very dangerous.
Shoot them and get out of the way. Pulsar tankers are also very dangerous. You can differentiate between the types of tankers by looking closely at their centers. Fuseball and pulsar tankers have tiny pictures of their cargos in their centers. The ability to instantly differentiate between tanker types is probably the most important ability separating good Tempest players from great Tempest players.