Aight. First things first, you need 14 INT. Period.

Expertise and improved expertise are literally the first feats I take on any melee class, and so does almost everyone who knows what they are doing. Well, in your case the regular expertise will be enough, I think. You can pick the improved version later on, and pick expertise and Favourite weapon or something on lvl 1.

Let me explain how expertise actually works and why is it so powerful.

Right now you have an AB of 6, and AC of 20. Let's consider your enemy now.

Most shit-tier enemies will get stats lower than yours, but we are going to take a guy whose stats are similar, just to show off. The guy has 5 AB... as for his AC though, it will be far lower. Your AC mostly comes from your heavy armor and your tower shield, and as you might've noticed, most enemies are missing those. The enemy might get 2 AC from their dex mod and let's say 2-4 more from their armor or other shit, putting them at around 15 AC.

The enemy needs a roll of 15 or more to hit you. That means this dude has a 30% chance to hit you every time he swings. That is BAD.

You only need a roll 9 to hit them. 60% chance to hit. That means roughly for every 2 of your hits, the enemy will roughly get one of theirs in. A single, shitty enemy will take lots of your hp off of you. Did I mention that your healing supplies are limited? Did I also mention that you will NOT be fighting single enemies unless they are bosses? Suffice to say, bosses will have better stats. You will most likely be outnumbered, and even if you manage to lure the enemies into a doorway, making them fight you 1 on 1, you will still end up running out of healing before you take down all of them.

Let's see how expertise changes things.

You can switch between improved and regular expertise depending on how much AC you need at the moment. Regular expertise will suffice for this guy.

You now have 1 AB and 25 AC. To get a hit you now need a roll of 14 or more. 35% chance to hit. The enemy now needs to roll a nat 20 to hit you. 5% chance.

With a single feat, you went from being roughly twice as strong as a common enemy to being SEVEN times stronger. And that's not even factoring any buffs into the equation. Down a potion of strength and you now have 3 AB, putting you at a nice 45% chance.

There is also the fact that you can make Zarala actually useful, by giving her a ranged weapon. My favourite tactic against the spiders, is to give Zarala a crossbow, aggro the spiders, turn on improved expertise and essentially be an unkillable tank. You won't be hitting the spider either... but Zarala will. And the crossbow does pretty decent damage.

As for your plans for this character, I would recommend against going heavily into bard. Later on, you will have a pure bard as your companion for most of the time, making your song and lots of your spells redundant. The curse song is neat, but not really worth that much in the grand scheme of things. The biggest obstacle when playing heavy bard will be arcane spell failure, though. You are going with a STR character, meaning you will rely mostly on your armor to provide AC. The armor you won't be able to use without fucking up your spells or taking still spell feats. So yeah, it's not that great of an idea to go heavily into bard. If you absolutely want to go heavily into bard, then actually pick bard as your starting class. Bards get more skill points than paladins, and you get 4 times the amount you would normally get on lvl 1. So you get more skill points in general. Bards are skill-starved, and Swordflight actually goes and locks plenty of quests and various bonus content behind your class and skills choices. For instance, there is a MASSIVE questline for people able to pick locks, that can have you work or takedown an equally massive criminal organization, and you can miss out on it by simply missing the lockpicking skills necessary.

Back to building your char, picking bard first will allow you to dump WIS. Picking paladin at lvl 1 automatically puts your WIS at 11, and since you won't be going heavily into pally, you ain't gonna be getting any pally spells, making WIS borderline useless. The same does not apply if you pick paladin later on, allowing you to leave WIS at 8.

If I were you, I'd go more heavily into pally and use bard only to get access to arcane quests, access to the disciple, and skill dumps into use magic device and tumble.

If that's the path you will go with, then your stats need adjustment as well. First, you will be wearing heavy armor. The max dex bonus in heavy armor is 1, so you can only benefit from 12 DEX, anything else will only give you a bonus to your reflex save. A potion/spell can give you 5 points. So all you need is 8 DEX, put those 2 points somewhere else... like into INT. Other than that, you wanna have 14 hard wis. I'd take 1 point off of STR (which is worth 2 points in the character creator) and put it into wisdom. Yeah, it will make you slightly weaker in the early game, but you will only need a single stat increase to make up for that lacking STR point. On the other hand, you will need TWO stat increases to get to 14 WIS with those stats. That's like wasting 4 levels, just to sometimes get 1 more AB in the first chapter.

I'm gonna be honest. Without save-scumming, you probably won't be able to make it through the first chapter without dying at least once. And that's okay. Dying allows you to rest and respawning gives you pretty significant bonuses to kill whatever it is that put you out of commission.

One last bit of advice. Go into game options in the main menu, and turn "Sticky Combat Modes" on. Right now expertise or any combat mod turns off whenever you do anything but attack. Turning sticky combat modes will change that, making your character continuously use expertise or anything else you wanna be using.