Icelandic forward Helguson, whose days in west London appeared to be numbered when he was farmed out to Watford last season, was ice-cool from the penalty spot in the first half and Hall, who spent the end of the campaign on loan at Newcastle, tapped in the fourth.
In between, former Plymouth forward Mackie opened his account with a predatory strike and Taarabt, who completed his permanent switch from Tottenham on Thursday, capped a sparkling display by tucking away the hosts' second spot-kick.
Despite the scoreline Barnsley will feel hard done by, with Jason Shackell and Adam Hammill both rattling the woodwork with Rangers just 1-0 up.
Home boss Neil Warnock handed out five debuts and his new-look side were first on the attack with Argentinian midfielder Alejandro Faurlin firing narrowly wide.
Barnsley's first chance came from a corner from Jay McEveley which Nathan Doyle nodded wide, before Rangers new boy Clint Hill shaved the crossbar with a header.
Taarabt, who frustrated and delighted in equal measure during a loan spell at Loftus Road last season, had adopted his familiar shoot-on-sight policy and forced two fine saves from Tykes goalkeeper Luke Steele.
The opening goal came in the 40th minute when Taarabt twisted and turned past Shackell in the area before being sent sprawling to the turf by Stephen Foster.
Warnock remains in the market for a striker before the end of the transfer window but Helguson reminded the manager he is still around by sending Steele the wrong way from the spot.
The Tykes should have forced a leveller just before the break when Rangers goalkeeper Paddy Kenny spilled a routine catch but Shackell's header came back off the post.
They almost stunned Rangers 30 seconds after the restart when Hammill strode forward and crashed his shot against the upright.
Barnsley also had a shout for a penalty for a handball against Hall but their claims were waved away.
Instead the hosts went two ahead in the 54th minute when Faurlin and Hogan Ephraim combined to set up Mackie, who made no mistake in front of goal.
In the 62nd minute Doyle was caught in possession by Helguson in the area and brought the Rangers striker down, allowing Taarabt to confidently beat Steele from the spot.
Helguson should have hit the fourth but came up with an early contender for miss of the season when he fluffed Taarabt's cross from all of three yards out.
So it was left to newly-appointed skipper Hall to complete the scoring from close range 10 minutes from time.