Ideas on Warlock use of bonus action by multiclassing with a Bard (Barlock)

In a party with a level 3 Warlock Tiefling – The Fiend (Pact of the Tome) with the cantrips: Eldritch Blast, Vicious Mockery, Minor Illusion, Chill Touch, Spare the Dying and Thaumaturgy. Hex as 1st level and at 2nd level Darkness and Hellish Rebuke. (Other members are: 1 Ranger, 1 Barbarian, 1 Paladin, so pretty much focused on close combat and the Warlock with the Ranger from a distance) We are noticing that the party members benefit more from bonus actions than the Warlock. Since that member is the only caster barely using weapons and solely their spells we are discussing the options to multiclass with a Bard next level and at 4th level get the Telekinetic feat (from Tasha’s Cauldron of Everything) to move creatures 5ft. Being able to use bardic inspiration would seem the quickest and most useful mechanically-wise using all elements of the turn (action, bonus action, move, etc.). Online it mentions multiclassing with a sorcerer as well to use metamagic, which happens at level 3 taking more time than multiclassing with a bard, but that could be the next step.

So, question 1: What options does a Warlock have for bonus actions apart from Hex or other spells?

Question 2: What are the experiences of multiclassing with a Bard level 1 or till another level, despite main focus on Warlock until level 5-7.

Question 3: What are the online experiences with Warlock, but also a 1st level Bard and 3 levels of Sorcerer?