1. Withers can respec all characters you play and change them to level 1 with the class & attributes you want for 100 gold per person. They keep their exp so you can level them right back up again.
2. Loads of different scenarios happen depending on your conversations and who does them, what stats you have and what successes you get on dice rolls. Sometimes a dice roll alone isn't enough and you need a extra check to go your way.
3. You can, in the camp, click on your party members icon to control them an talk with others.
4. Barrelmancy is insanely strong. Stock up on some explosive barrels by right clicking them and pick them up and then send to camp. If you find a problem in the road try blasting it to space.
5. Clerics are insane. Free legendary weapon at level 11? Yes please. "Free" unlimited supply of legendary weapons and potions through Withers recruits as Clerics? Yes please. Blood of Lethander for a automated revive every long rest, that also heals allies when you go down, and with Lethanders light that blinds enemies within a 6 meter radius (basically a bit above melee range) to make them less likely to hit you and you more likely to hit them... On top of a goddamn level 6 spell in Sunbeam to blast foes into the depths of hell, Glyph of warding (all elemental damages in aoe), Spirit guardians so you can even do damage while getting close to enemies.you can even summon helpers to take some focus off. Insane amounts of heals with Beacon of Hope + Prayer of healing from the life domain? Don't even need to with the life domain special healing, but why not both just in case. Banish to remove a toxic enemy? Sweet music in my ears. Cantrips like sacred flame and fire bolt to keep range damage up in fights you otherwise want to save spells on? Yaaas.
If you don't like it to be a very supportive one you can spec into light domain and get more damage spells, not that I'd know why you'd want to when you can have everything on a life cleric.
Want to be even more destructive against a boss? Multiclass into paladin x2 to get thunderous smite with luck of the far realms to guarantee a crit into a divine smite. Tons and tons of damage. Get gloves of dexterity and you can drop your dex to 8 and invest more into str or constitution and avoid having to move last every fight. Again, you can respec as you get the gear, 100 gold is nothing.
Hell, I'm running both a smiter and a pure life cleric in my party while pushing enemies back hard with eldritch blast from my fighter/warlock Karlach built to keep enemies spread out while being a capable fighter in close quarters. Gale kills everything with fireballs unless i expect an enemy to be difficult, then he also has banish so that they can be focused later.
Basicaly builds and classes in general don't start to matter beyond level 5 as the power you get from there and up is just so massive compared to the beginning. As long as you don't reroll your party into stats that actively doesn't work for them then you should look for different approaches (targets, dialogue options, maybe explore a different area) if you get stuck as it is very unlikely to be down to your build early on unless you are playing on tactician.