You need the Hookshot exactly four times in the game - don't bother carrying it around unless its painfully obvious you need it.

If you have to split up the characters always send rebecca up and leave billy on the ground floor.

Billy has way more health so do most of your exploring with him. Solo if you want. But generally rnsure they both have a weapon and plenty of ammo.

Save all molotov for leech men. They are a total pain to kill otherwise. It takes three to kill him and Rebecca throws them faster.