Lots of good advice here. I have just a few suggestions to add.
First, do as your players have asked--slow down! Let them make meaningful connections to their characters, each other, and some NPCs. Don't rush it. And rather than feel compelled to level them up, instead try to level the adventure down where necessary.
Second, create connections between the characters and giant factions. Make it personal. Give them some villains to hate. Maybe the stone giants killed the mentor of the elf ranger, the dwarf cleric discovers his blacksmith brother is a captive of the fire giants, the half-elf's village is starving due to hill giant raids, and the sorcerer hears about a potent magic item in the frost giant's iceberg lair. Maybe they see all of this in an Oracle the vision presents to them.
Third, and this is just personal preference, have the Oracle point them toward the lairs of the giants rather than the burial mounds of the barbarians. The burial mounds will just continue to make the players (and you) feel like the adventure is aimless. At this point, it's probably best to take the fight straight to the giants.
Fourth, six characters at 7th level are pretty formidable. They should be able to take on the hill giants and have a fighting chance in several of the other lairs if they play it smart and you scale back a few of the challenges.
Fifth, once the characters have proven their meddle against a few of the giants and you're feeling like it's time to begin moving things to a close, then you can introduce the Maelstrom, King Hekaton, and the endgame for the adventure.
Hope that helps.
First, do as your players have asked--slow down! Let them make meaningful connections to their characters, each other, and some NPCs. Don't rush it. And rather than feel compelled to level them up, instead try to level the adventure down where necessary.
Second, create connections between the characters and giant factions. Make it personal. Give them some villains to hate. Maybe the stone giants killed the mentor of the elf ranger, the dwarf cleric discovers his blacksmith brother is a captive of the fire giants, the half-elf's village is starving due to hill giant raids, and the sorcerer hears about a potent magic item in the frost giant's iceberg lair. Maybe they see all of this in an Oracle the vision presents to them.
Third, and this is just personal preference, have the Oracle point them toward the lairs of the giants rather than the burial mounds of the barbarians. The burial mounds will just continue to make the players (and you) feel like the adventure is aimless. At this point, it's probably best to take the fight straight to the giants.
Fourth, six characters at 7th level are pretty formidable. They should be able to take on the hill giants and have a fighting chance in several of the other lairs if they play it smart and you scale back a few of the challenges.
Fifth, once the characters have proven their meddle against a few of the giants and you're feeling like it's time to begin moving things to a close, then you can introduce the Maelstrom, King Hekaton, and the endgame for the adventure.
Hope that helps.