I was annoyed that this option was a Game Over; it could just as easily have turned into Garth coming over and asking you more directly to help this person, maybe even bribing you in some fashion (while the other two options gave you different bribes, such as a "courage bonus" to your stats instead of a piece of equipment). Just because Kass is the big bad doesn't mean that a level 1 character should immediately go out and attack "it"; you'll keep hearing about what's going on and should eventually come to the conclusion that you need to do something, but not that early.
Why should it not be a Game Over? Like how in the Far Cry games where you need to do something in the beginning, if you don't do it then the events of the story turn out totally different. Sure, Kass appears either way, but the entire reason for your character to engage vanishes if you don't go with Cait at the start. And as for the bribing/asking, why should Garth? There's several patrons at the bar, and the PC is completely unimportant before heading to the temple with Cait, so there's nothing of interest to get Garth to ask you. And several storybeats do not work without the PC's presence at the temple. The writers should not have to rewrite huge chunks of the story to accommodate a choice which indicates disinterest in game's plot.
Well that's a bit of an issue. A smaller party should have the advantage in issues like stealth, and if lone enemies get extra actions then so should a lone player.
It's not an issue. You don't get stealth bonuses to combat or something like that beyond specific abilities, and there's few occasions where stealth is even an option outside of combat, and those are never penalized by who your companions are (though certain companions may instead support alternative options). This is a game in which you are expected to always have a full party, and if you don't want to engage with it as such (like I did back when I first played, back when the Foothills were the only available area with combat), then, well, tough. If you play Dark Souls at soul level 1, the game shouldn't make everything easier to accommodate your choice.
Avoiding an unnecessary combat should be nearly as rewarding as defeating it in many cases. Otherwise the players turn into murderhobos.
Murderhobos are a problem in a TTRPG where the story can be actively hurt by resorting to violence. In instances where the story is actively hurt be resorting to violence in a game like this, options get laid out which allow the player to see that there are viable alternatives
in that situation to violence. Murderhobos are born from a scenario where peaceful solutions are discouraged when one would think it viable, but this game clearly marks where it is or isn't simply by the choices it presents to the player.
That doesn't really work unless you have a tank in your party. And my warrior character is a terrible tank for some reason. My other characters all recruit Brint, but he can't really actively tank for anyone else in any way I've managed to find out. Only warriors get Guarded Stance, I think?
1: If you want to be more tanky, buy armor. You start out with the Comfortable Clothes, which are tied for the lowest armor of the whole game (15), while also having the lowest evasion of any non-heavy armor (5). With your starting money (after you beat the tutorial and sell excess items), you should have enough to afford most of the armor items available for sale from Leorah and Ogrish, and even if you don't sell anything you should have enough for the leather coat, which has 35 armor and 20 evasion.
2: If you want a different character to tank, Atugia is the third easiest companion to recruit. Cait you start out recruited, and Brint you recruit by literally just walking into the forest, and Atugia? She's in Hawkethorne. If you go to the far right, and then go up, and continue along that path past the temple where you fought Tollus, you'll encounter her. If you're level 1 you'll almost certainly lose but there's literally no negative impacts (storywise and mechanically) for if you lose in this fight, and then you can talk to her. It is a bit rng dependent but if you enter and exit the tile she's in repeatedly some events should occur (you've said your character's a straight man so this should be fine to you) and you can recruit her. He role is to tank, and she does so quite well.
Hence why I don't always recruit Brint.
Again, I don't always have time to flee after I start losing (enemy 1 knocks down the healer, enemy 2 knocks down my guy, I never even get an action), and fleeing doesn't always succeed, so a failed effort gives the enemy two more attacks before I get another turn. It's pretty fucking dangerous; even a fairly beef level 3 party of two can lose against a lone level 2 monster.
Engage with the game the way the game is supposed to be engaged with. It's not going to accommodate your choice to not engage with it the way it's supposed to be engaged with.
But this means replacing your own innate. If you're a White Mage, you'll probably need Heal way more; if you're a Black Mage, Withering Bolt may well still be more useful. Only the Charmer seems really likely to be worth training away his innate (and maybe Warriors if you have Brint and Cait), and frankly all of the Charmer's powers look kind of useless to me (this was exactly why I recruited both Brint and Cait for my Charmer, which is probably why he's doing better than my other two-character parties).
Charmers are intended to be the non-combatant combatant. They're Presence focused, which is the stat that boosts your ally's stats and boosts your character's sexiness, and their powers are things which fit this role: Bolstering Dance buffs your whole team's survivability, both against physical and mental attacks (also it's one of a few abilities which restore resolve damage rather than physical damage, which is useful against teasing enemies), and the the Charmer gets two alternative at-wills at level four. One is Soothing Dance, which is straight up just Heal but for resolve and the Aroused condition rather than health and the Bleeding condition. The other is Song of Courage, which goes harder support aspect with no constantly active resolve heal. War Song is an aoe resolve hit, and even if you don't use it to fight with resolve, its status effect. Song of Storms can be used to buff yourself, but it's also able to target allies, which is especially useful with Brint since he's weapon-focused. The Charmer stays this way throughout, excelling at supporting allies and dealing resolve damage, and while the latter isn't quite intended with your starting teammates, they can still work with it as their own tease attacks aren't weak. They aren't useless, they're just different, in a perfectly viable way.
That said, replacing your class abilities with those of another class are useful in certain situations. My main character is a Warrior who focused hard on the damage-dealing aspect, and to support this I swapped out the at-will with the White Mage's Charge Weapon, so she hits even harder with all her abilities.